How to get MOB back into an X????
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waternwaves
- Admiral
- Posts: 1499
- Joined: Wed Oct 13, 2004 8:18 pm
- Location: X less in North Puget Sound -have to sail other boats for a while
Nope...have todisagree on this one....have to maintain control of the boat..
2 people sailing, one falls overboard.....she isnit going to get into a dink to try and pull me back in...for one..the dink is not stable enough to land someone unconscious and in conditions of falling overboard entering the dink is probably not safe anyway.....who is controlling the boat.
Winching/pulling to the transom of an inflatable is not going to bring someone over the tube...it will jsut pull into the tube... The inflatable has enough bouyancy, but the form will dump you in the drink........been there, tried that.......got the shirt........
Hauling up the backstay works.......
It was able to lift and slide me against the hull, and and flopping in is ungainly...in....not pretty, probably too slow..(used a vang....) but it works.....
Plus if you are snagging them with the boat hook anyway....it is the easiest way to get a line on someone unconscious already in a harness...
But I cant see the advantage of the remaining person leaving the cockpit to try to rescue...... Maybe I am just old and slow.....
2 people sailing, one falls overboard.....she isnit going to get into a dink to try and pull me back in...for one..the dink is not stable enough to land someone unconscious and in conditions of falling overboard entering the dink is probably not safe anyway.....who is controlling the boat.
Winching/pulling to the transom of an inflatable is not going to bring someone over the tube...it will jsut pull into the tube... The inflatable has enough bouyancy, but the form will dump you in the drink........been there, tried that.......got the shirt........
Hauling up the backstay works.......
It was able to lift and slide me against the hull, and and flopping in is ungainly...in....not pretty, probably too slow..(used a vang....) but it works.....
Plus if you are snagging them with the boat hook anyway....it is the easiest way to get a line on someone unconscious already in a harness...
But I cant see the advantage of the remaining person leaving the cockpit to try to rescue...... Maybe I am just old and slow.....
waternwaves....in detail,
how did you fix the tang to the backstay and what did you use as the tang?
I would like to copy your arrangement, but need more details.
Thanks
Ron
I would like to copy your arrangement, but need more details.
Thanks
Ron
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waternwaves
- Admiral
- Posts: 1499
- Joined: Wed Oct 13, 2004 8:18 pm
- Location: X less in North Puget Sound -have to sail other boats for a while
Ugly mcgyverisms.....
Since I was sailing by myself.., it originally started as my clip in point for my harness last winter off of vancouver island...
I see that stainless wire rope clamps are available at West marine.....
And yes it is ugly....
however I had a bunch of galvanized 1/8" wire rope clamps and a spare hank of stainless wire....about 24 inches..., the two clamps are about 6 inches apart..., hang on there all the time now...and my harness or spare vang with chock clip in with a biner....
If the mast was up and I was near the boat I would take a pic..but I am working in seattle this week and no time for the boat...., need to stop by west marine this weekend and replace the rusty galvanized pieces with with true SS wirerope clamps.
I see that stainless wire rope clamps are available at West marine.....
And yes it is ugly....
however I had a bunch of galvanized 1/8" wire rope clamps and a spare hank of stainless wire....about 24 inches..., the two clamps are about 6 inches apart..., hang on there all the time now...and my harness or spare vang with chock clip in with a biner....
If the mast was up and I was near the boat I would take a pic..but I am working in seattle this week and no time for the boat...., need to stop by west marine this weekend and replace the rusty galvanized pieces with with true SS wirerope clamps.
- MAC26X
- Chief Steward
- Posts: 89
- Joined: Fri Dec 31, 2004 12:57 pm
- Location: Sandusky, OH 2001 Mac26X Anne Marie Honda 50
Waternwaves:
I think you altered my theory about using a life raft. If 2 are sailing and 1 falls overboard I certainly didn't intend the rescuer to enter the dink. The rescuer simply deploys a self-inflating life raft and secures it from both ends to the sailboat. Then a boathook or winch can be used, possibly along with a stay or boom to get the person into the raft. The rescuer, especially without assistance would never leave the sailboat. A tired and cold MOB could possibly help get themselves into the raft but would be of little help in a dead lift vertically over the side or stern. The important thing is that once they are in the raft the emergency is reduced.
I think you altered my theory about using a life raft. If 2 are sailing and 1 falls overboard I certainly didn't intend the rescuer to enter the dink. The rescuer simply deploys a self-inflating life raft and secures it from both ends to the sailboat. Then a boathook or winch can be used, possibly along with a stay or boom to get the person into the raft. The rescuer, especially without assistance would never leave the sailboat. A tired and cold MOB could possibly help get themselves into the raft but would be of little help in a dead lift vertically over the side or stern. The important thing is that once they are in the raft the emergency is reduced.
- Jeff Stagg
- Deckhand
- Posts: 38
- Joined: Sat Jan 24, 2004 10:32 am
- Location: Roseville, CA USA
MOB links
The discussion of Man Overboard (MOB) is endless. I have tossed a PFDIV flotation cushion overboard and asked any number of crew to "rescue" it, pretty much to no avail whether under power or sail. Just trying to retrieve a lost hat makes for some precise maneuvering as well. Nevertheless, all of this is moot if the Captain goes overboard and there is no crew to attempt a rescue. In this case, as skillfully written a few posts back, staying on the boat or at least attached to the boat, is the only means of self-preservation: jacklines, tethers and harnesses, and no motor on, of course. Even here, if knocked out as Chip mentions, at least you'll be attached to the boat, and afloat.
Most everything I've seen refers to the Lifesling using the Instant Stop method by putting the boat into irons. Some use the figure 8 (Sail Magazine) and tack back. This is the most chance to lose sight of the MOB and, if you lose forward motion in a Mac, you are not going to tack with the windage on the hull, rather, you'll drift to leeward and go into a run, necessitating tacking back to the MOB.
Hence, if the GPS is on, hit the "Mark" or "Go To" button, toss a couple of PFDIV cushions like a frisbee upwind of the MOB and if no light attached to the cushion or MOB, toss a floating light or spotlight if it's dark. NOW, deploy the Lifesling and circle the MOB. I have practiced steering the boat backwards, that is, put her in irons, keep the head down, and as the boat drifts aft, steer to keep in irons. Fully tightening the mainsail will keep the boat in irons or close to it if you need to leave the wheel for Lifesling deployment.
Use a Lifesling 3:1 tackle or the mainsheet or boom vang 4:1 tackle to hoist the MOB as close to the winch as possible to secure the chest above the water and buy some time. There are a couple of winch style hoists with poles available on the net for some hefty bucks.
It remains to be determined whether using the boom or a (jib!) halyard would be adequate to raise a MOB over the side and into the cockpit. In rough weather it is not recommended to attempt a transom boarding (see link below).
Here is an in-depth (no pun intended
) and extensive article on two person with one overboard and rescue techniques. It has detailed info about surviving in the water and getting rescued with statistics and times for trials by novices: http://www.ussailing.org/safety/Studies ... artips.htm
Here is the Lifesling tackle, similar to our boom vang (you use snap hooks to attach when rigging, right?) Scroll down to "Lifesling tackle for Sailboats" to see a photo and then click on that photo link for the rest of the text: http://www.westmarine.com/webapp/wcs/st ... chDeptId=8
I only raise the sails with the motor off; same for lowering, but then only when heaved to to steady the boat. If I go over, I can get back on; not so with the motor on. If there is crew onboard who can safely (and legally, age 16 in CA) operate the motor/controls, then I will have the boat motored into the wind for sail handling. My methods may take longer, but I have spent many hours thinking about the "what ifs" of being overboard whether single handed or not, and have devised these techniques for peace of mind.
BTW, never step on a sail lying on the deck, and keep your feet on the non-skid: avoid the black smooth areas around the windows, especially if wet or waxed. I'll never forget how fast I went down doing these two things...please just take my word for it instead of testing for yourself
Also, ban flip flops from the boat, they slide on wet surfaces. The $5.00 water shoes (not the new ones with the cloth center sole) or Sperrys are good. There are some new sandals that are probably cooler, but I haven't tried them.
Good sailing, and keep yer butt secured to the boat,
Most everything I've seen refers to the Lifesling using the Instant Stop method by putting the boat into irons. Some use the figure 8 (Sail Magazine) and tack back. This is the most chance to lose sight of the MOB and, if you lose forward motion in a Mac, you are not going to tack with the windage on the hull, rather, you'll drift to leeward and go into a run, necessitating tacking back to the MOB.
Hence, if the GPS is on, hit the "Mark" or "Go To" button, toss a couple of PFDIV cushions like a frisbee upwind of the MOB and if no light attached to the cushion or MOB, toss a floating light or spotlight if it's dark. NOW, deploy the Lifesling and circle the MOB. I have practiced steering the boat backwards, that is, put her in irons, keep the head down, and as the boat drifts aft, steer to keep in irons. Fully tightening the mainsail will keep the boat in irons or close to it if you need to leave the wheel for Lifesling deployment.
Use a Lifesling 3:1 tackle or the mainsheet or boom vang 4:1 tackle to hoist the MOB as close to the winch as possible to secure the chest above the water and buy some time. There are a couple of winch style hoists with poles available on the net for some hefty bucks.
It remains to be determined whether using the boom or a (jib!) halyard would be adequate to raise a MOB over the side and into the cockpit. In rough weather it is not recommended to attempt a transom boarding (see link below).
Here is an in-depth (no pun intended
Here is the Lifesling tackle, similar to our boom vang (you use snap hooks to attach when rigging, right?) Scroll down to "Lifesling tackle for Sailboats" to see a photo and then click on that photo link for the rest of the text: http://www.westmarine.com/webapp/wcs/st ... chDeptId=8
I only raise the sails with the motor off; same for lowering, but then only when heaved to to steady the boat. If I go over, I can get back on; not so with the motor on. If there is crew onboard who can safely (and legally, age 16 in CA) operate the motor/controls, then I will have the boat motored into the wind for sail handling. My methods may take longer, but I have spent many hours thinking about the "what ifs" of being overboard whether single handed or not, and have devised these techniques for peace of mind.
BTW, never step on a sail lying on the deck, and keep your feet on the non-skid: avoid the black smooth areas around the windows, especially if wet or waxed. I'll never forget how fast I went down doing these two things...please just take my word for it instead of testing for yourself
Also, ban flip flops from the boat, they slide on wet surfaces. The $5.00 water shoes (not the new ones with the cloth center sole) or Sperrys are good. There are some new sandals that are probably cooler, but I haven't tried them.
Good sailing, and keep yer butt secured to the boat,
- craiglaforce
- Captain
- Posts: 831
- Joined: Fri Jan 02, 2004 8:30 am
- Sailboat: MacGregor 26X
- Location: Houston, Tx
OK here's another simple method I thought of the other day.
you take your spare length of 1/2 inch anchor line or whatever and loop it around the port winch once. attach one end to your sailing harness and simply hold the other end. Climb down the swim ladder and grab the MOB. Go under and position the MOB for a fireman's carry. then using the power of your legs on the ladder, hoist both you and the MOB up the ladder, while pulling on the free end of the anchor line , taken across the small of your back and held by the hand that it also doing the fireman carry. You should get 2:1 mechanicaladvantage when pulling on the rope, can secure it for the next grab easily, and use leg power to get up over the stern.
Link below shows the firmans's carry.
http://www.vnh.org/StandardFirstAid/chapter11.html
you take your spare length of 1/2 inch anchor line or whatever and loop it around the port winch once. attach one end to your sailing harness and simply hold the other end. Climb down the swim ladder and grab the MOB. Go under and position the MOB for a fireman's carry. then using the power of your legs on the ladder, hoist both you and the MOB up the ladder, while pulling on the free end of the anchor line , taken across the small of your back and held by the hand that it also doing the fireman carry. You should get 2:1 mechanicaladvantage when pulling on the rope, can secure it for the next grab easily, and use leg power to get up over the stern.
Link below shows the firmans's carry.
http://www.vnh.org/StandardFirstAid/chapter11.html
Craig,
I'm having trouble seeing the 2:1 advantage...
One end tied to your harness,
Looped around the winch, and
pulling on the other end - Won't give you a 2:1 advantage...
It is still 1:1...
You said something about the small of your back, and maybe that's what I'm not understanding...
Also, if you're going to loop it around the winch, you need to be careful to loop it in the right direction, as my winch only turns one way. If you get it backwards, you will also be fighting the friction of the line against the knurled winch surface...
I'm having trouble seeing the 2:1 advantage...
One end tied to your harness,
Looped around the winch, and
pulling on the other end - Won't give you a 2:1 advantage...
It is still 1:1...
You said something about the small of your back, and maybe that's what I'm not understanding...
Also, if you're going to loop it around the winch, you need to be careful to loop it in the right direction, as my winch only turns one way. If you get it backwards, you will also be fighting the friction of the line against the knurled winch surface...
- Chip Hindes
- Admiral
- Posts: 2166
- Joined: Mon Jan 05, 2004 6:13 am
- Location: West Sand Lake, NY '01X, "Nextboat" 50HP Tohatsu
No, he's right; pulling yourself up on a single block is a special case of 2:1.One end tied to your harness,
Looped around the winch, and
pulling on the other end - Won't give you a 2:1 advantage...
It is still 1:1...
However, the idea you could climb the ladder with somebody on your back, fireman's carry or any other method, while using no hands to hold the person on your back, no hands on the ladder, but both hands pulling on the free end of the line?
2:1 won't help. I don't believe it's even marginally feasible.
Besides which, going into the water to assist a COB would be considered a desparate measure, a truly last resort. More likely, you'll now be dealing with two COB instead of one.
- John Skardzius
- Just Enlisted
- Posts: 23
- Joined: Fri Jan 02, 2004 6:58 pm
- Location: Burlington, Ontario, Canada
Real World view of MOB
Hello everyone. I had the opportunity to look at this from a MOB perspective last week. Took a swim in 2 foot waves, water temp 75 degrees, sunny, 2 miles from shore. Shorts, T-shirt. Well, forst thing you do is look up.....WAY UP! OK so 1st mate can't reach me by hand...barely so if I outstretch my arm...ooopss....a wave! try again....oops another one. OK so I'll swim to the back of the boat....ooops boat is drifting....man I have to get back into shape! There. I'm there now...hold on to boarding handle (everyone has one of these, right?) oops wave....ouch that motor is hard! OK 1 foot onto the swim ladder (with welded on SS platforms on the rungs) Uh...boy I'm heavy! 1-2-3...there! I'm aboad! Now to move the dang seat....aw fuggetaboutit!!!just leap over...its too wavey!
Now try this in adverse conditions...puts a new (and real) perspective on all of the discussed ways of doing things.
Point being if MOB is disabled, there is no way of getting to them and getting a line on them from WAY up there.
Try it.
So, POB (crew,admirla, etc.) gets a tether, goes overboard, secures MOB and then tries the various "get 'em on the boat" options.
It ain't pretty. 2 thougts come out of this
1) Find as many ways to stay on the boat as possible...review methods especially if Single Handed
2) Time to completely re-evaluate the MOB drill...back to the drawing board.
Now try this in adverse conditions...puts a new (and real) perspective on all of the discussed ways of doing things.
Point being if MOB is disabled, there is no way of getting to them and getting a line on them from WAY up there.
Try it.
So, POB (crew,admirla, etc.) gets a tether, goes overboard, secures MOB and then tries the various "get 'em on the boat" options.
It ain't pretty. 2 thougts come out of this
1) Find as many ways to stay on the boat as possible...review methods especially if Single Handed
2) Time to completely re-evaluate the MOB drill...back to the drawing board.
Let me be the first to ackowledge that I may very well be dense and simply missing this...Chip Hindes wrote:No, he's right; pulling yourself up on a single block is a special case of 2:1.One end tied to your harness,
Looped around the winch, and
pulling on the other end - Won't give you a 2:1 advantage...
It is still 1:1...
But let me ask this:
If you secured the line to yourself, jumped off the boat, and had a crew member, still on the boat, pull you back aboard, without the use of blocks or winches, wouldn't they be pulling with no advantage, i.e.. 1:1? Here, your buddy is pulling the line 1 inch for every inch you come out of the water.
If that's wrong, please just ignore the rest of this or you will think I'm really stupid, even stupider than you now think I am.
If that's right:
Ok, now imagin yourself in the water at the transom and your buddy at the bow of the boat, still not using any blocks, etc., and still getting a 1:1 advantage. Here, your buddy is still pulling the line 1 inch for every inch you come out of the water.
Ok, now imagine that your buddy wrapped the line around the port winch (how many times he wraps it doesn't matter, in this case as described) and is standing on the starboard side of the boat, such that the line turns 90 degrees at the port winch. Here, he still gets no advantage, pulling on the line by hand. (Yes, he'd get the winch's advantage if he wrapped the line around the winch several times and used the winch to pull, but forget that for the moment.) Here, with the winch turning the line 90 degrees, your buddy is still pulling the line 1 inch for every inch you come out of the water.
[incidentally, if your buddy used the starboard winch and was standing on the port side, in the above example, he would be pulling against the winch, thereby fighting the friction of the line against the knurled winch surface... At least I believe my boat's winches only turn clockwise IIRC.]
Ok, back to our story, if your buddy moves to the transom, with the line still wrapped around the port winch, but no other blocks, wouldn't he still be getting no advantage, i.e. 1:1? Wouldn't you come out of the water 1 inch for every inch of line he pulls?
What if he reaches down and hands you the line?
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Frank C
Pardon my pessimism, but this problem is pretty close to futile (as John's little test revealed) but it's especially futile when the Mate is 100# and the MOB is 180#. Considering reality for a minute, with my 26X ...
A winch at the mid-stanchion could solve this problem with electricity ... that's terrific!. But just as a feasibilty test, stand next to your boat on the trailer. Now use that horizontal mid-stanchion to chin yourself, and just try to get yourself aboard. Futile? Well ... maybe a hand from that cute little hundred-pounder would make the magic difference ??? ... Nope - still futile! She can motor home though as you hang from yer chin!
Now imagine that the boom is extended 12 to 15 inches ABOVE that mid-stanchion. As the MOB is lifted from the water (shackled to a boom line), does anyone think the hull will heel, dropping the rail by 8 to 12 inches? I do. So it's still like chinning yourself on that horizontal stanchion, but you're 18 to 24 inches outboard from it. It's not that I WANT to throw a wet blanket over these plans ... it's just that I believe that they're truly unrealistic - dangerous pablum to assuage valid fears that remain truly unsolved.
I actually did rescue a young lady once from SF Bay. She was a 110# wisp. I can guarantee it would have required 2 crew and 4 biceps (both my crew and myself) to hoist her over the side of the cockpit. Fortunately, she & her boyfriend had been in the water for only five minutes at their capsized sailing dinghy. Also very fortunate, the conditions were mild, so I could kill the motor, not just "neutral it." She was able-bodied enough to simply climb my swim ladder & sit wrapped in a beach towel. Boyfriend continued trying to right his boat until the Coasties forced him aboard their vessel, and took his under tow.
Fortunately, only the unluckiest of us will ever be faced with a completely immobile or unconcious MOB. FWIW, there's no way I'd try to recover anyone, in any condition, except across the transom. (In this regard, I believe that the 26X has an advantage over the 26M). In order to accomplish EVEN THAT, I'll be praying the MOB's able to put a foot on the ladder & help themselves.
Best of luck, and hoping your contingency plans are realistic.
A winch at the mid-stanchion could solve this problem with electricity ... that's terrific!. But just as a feasibilty test, stand next to your boat on the trailer. Now use that horizontal mid-stanchion to chin yourself, and just try to get yourself aboard. Futile? Well ... maybe a hand from that cute little hundred-pounder would make the magic difference ??? ... Nope - still futile! She can motor home though as you hang from yer chin!
Now imagine that the boom is extended 12 to 15 inches ABOVE that mid-stanchion. As the MOB is lifted from the water (shackled to a boom line), does anyone think the hull will heel, dropping the rail by 8 to 12 inches? I do. So it's still like chinning yourself on that horizontal stanchion, but you're 18 to 24 inches outboard from it. It's not that I WANT to throw a wet blanket over these plans ... it's just that I believe that they're truly unrealistic - dangerous pablum to assuage valid fears that remain truly unsolved.
I actually did rescue a young lady once from SF Bay. She was a 110# wisp. I can guarantee it would have required 2 crew and 4 biceps (both my crew and myself) to hoist her over the side of the cockpit. Fortunately, she & her boyfriend had been in the water for only five minutes at their capsized sailing dinghy. Also very fortunate, the conditions were mild, so I could kill the motor, not just "neutral it." She was able-bodied enough to simply climb my swim ladder & sit wrapped in a beach towel. Boyfriend continued trying to right his boat until the Coasties forced him aboard their vessel, and took his under tow.
Fortunately, only the unluckiest of us will ever be faced with a completely immobile or unconcious MOB. FWIW, there's no way I'd try to recover anyone, in any condition, except across the transom. (In this regard, I believe that the 26X has an advantage over the 26M). In order to accomplish EVEN THAT, I'll be praying the MOB's able to put a foot on the ladder & help themselves.
Best of luck, and hoping your contingency plans are realistic.
Last edited by Frank C on Thu Aug 11, 2005 3:47 pm, edited 1 time in total.
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Frank C
It's very important to have enough "hoist" to help someone who's immobilized. I'm guessing the hoist distance is about 4 feet at the transom, versus maybe 7 feet over the side. No-brainer ... the only practical way to hoist a MOB is using an overhead tackle at the transom.
Assuming the backstay isn't too weak (a big uncertainty?) then it could provide an angled "drag-lift" to a MOB's harness. If the backstay is too weak, mainly a problem at the crane, it either needs reinforcement at the masthead, or I need an arch or davit at the stern. No other options seem practical, IMO.
My backstay splits at a point about 7 or 8 feet above water's surface, so a 4-foot lift is feasible. I think by re-designing the backstay's 8-to-1 tackle, it could be QUICKLY ADAPTED (?) for lifting a MOB instead of bending the mast. Might just need an extra shackle on the backstay tab at the port quarter. I need to get over to the boat and ponder this awhile ..... (hmmmmm).

Assuming the backstay isn't too weak (a big uncertainty?) then it could provide an angled "drag-lift" to a MOB's harness. If the backstay is too weak, mainly a problem at the crane, it either needs reinforcement at the masthead, or I need an arch or davit at the stern. No other options seem practical, IMO.
My backstay splits at a point about 7 or 8 feet above water's surface, so a 4-foot lift is feasible. I think by re-designing the backstay's 8-to-1 tackle, it could be QUICKLY ADAPTED (?) for lifting a MOB instead of bending the mast. Might just need an extra shackle on the backstay tab at the port quarter. I need to get over to the boat and ponder this awhile ..... (hmmmmm).
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Frank C
Actually it was quick to ponder and it's braindead easy for my backstay tackle ... just a little hard to describe. This still assumes the backstay crane is sturdy enough - probably a good bet since it only needs to "drag-lift" someone across the transom.
I have a "triangle-tackle" rigged from portside, up to backstay, down to starboard. There's a single block at the port quarter and a centered double block overhead at the backstay loop-end. The lifting tackle is between the overhead double-block and the starboard quarter tab.
Without describing every gory detail, trust that the port quarter has two lifting lines (pulling down on the mast) and the starboard has one line dead to the starboard quarter, and the other with a 4:1 vang tackle inserted.
The port quarter has a single block shackled to its stainless backstay tab. All that's needed is to insert a heavy-duty carabiner between that block and its portside backstay tab. Now I can quickly unsnap the portside backstay tackle and extend it down to the water surface. (I want to clip a replacement line to hold the backstay on center, or slightly to port .... else I'd just drag-lift a MOB over the starboard transom). The starboard lifting tackle provides the life-saving drag-lift. (Just in mind's eye, I believe it's a 12:1 purchase).
Look at it this way, 26X'rs ... now there's a doubly-good reason to install that high-overhead, split backstay you keep reading about! I'll try to remember to snap a picture, since I'm sure that description's a little cloudy
I have a "triangle-tackle" rigged from portside, up to backstay, down to starboard. There's a single block at the port quarter and a centered double block overhead at the backstay loop-end. The lifting tackle is between the overhead double-block and the starboard quarter tab.
Without describing every gory detail, trust that the port quarter has two lifting lines (pulling down on the mast) and the starboard has one line dead to the starboard quarter, and the other with a 4:1 vang tackle inserted.
The port quarter has a single block shackled to its stainless backstay tab. All that's needed is to insert a heavy-duty carabiner between that block and its portside backstay tab. Now I can quickly unsnap the portside backstay tackle and extend it down to the water surface. (I want to clip a replacement line to hold the backstay on center, or slightly to port .... else I'd just drag-lift a MOB over the starboard transom). The starboard lifting tackle provides the life-saving drag-lift. (Just in mind's eye, I believe it's a 12:1 purchase).
Look at it this way, 26X'rs ... now there's a doubly-good reason to install that high-overhead, split backstay you keep reading about! I'll try to remember to snap a picture, since I'm sure that description's a little cloudy
Frank, with the port side block disconnected and becoming the lifted point, your system is a 2:1 purchase pulled by a 4:1 vang. To lift the port side block 4' you have to take 8' out of the loop, so your 4:1 vang would have to start out with its blocks 8' apart and be pulled until they were touching. You'd pull 32' of line out of the 4:1 vang. The rescue purchase is 8:1.
When I say "the loop," I'm referring to the line that leaves the starboard transom goes up and over the double block down around the port side block, back up and over the double block, and back to the 4:1 vang.
[on edit] Actually, to get 4' lift at the port side block, you're going to also account for the sag of the backstay as weight gets on it, i.e. you're going to have to take nearly 4' out of the loop if the double-block sags a foot, meaning the 4:1 vang blocks will have to start out about 12' apart and you'll pull 48' out of it.
When I say "the loop," I'm referring to the line that leaves the starboard transom goes up and over the double block down around the port side block, back up and over the double block, and back to the 4:1 vang.
[on edit] Actually, to get 4' lift at the port side block, you're going to also account for the sag of the backstay as weight gets on it, i.e. you're going to have to take nearly 4' out of the loop if the double-block sags a foot, meaning the 4:1 vang blocks will have to start out about 12' apart and you'll pull 48' out of it.

