It is a little squirly

[Mark Prouty]

At about 15mph heading into the waves with a strong wind, the boat will turn and will need immediate correction. I know the wind/wave conditions where this occurs and can anticipate it.

What are others experience with this?

[Dimitri-2000X-Tampa]

I can't typically take waves (considering anything over about 1 foot to be a wave and not a chop) more than at about 10mph. It's usually quite steady at this speed but does cause a lot of spray on the dodger. If the waves are over 3 feet, speed drops down to half of that or else it starts dropping off of the wave and pounding. The waves I'm in are usually spaced pretty close together which make it difficult to plane over them.

[Mark Prouty]

I can't typically take waves (considering anything over about 1 foot to be a wave and not a chop) more than at about 10mph.

About the max speed for these conditions.

[deacm]

So.........what is the safe way to take waves then? You can't take them on the beam as that's a wobbly way to go.........taking waves from astern isn't much better than head on and pounding directly into them aint fun either. Deploy the hydrofoils? :-)

[Andy26M]

It is conditional, but I have found it more comfortable to sail in waves a few times. Seems like the boat "finds" the right angle to ride the waves that way - plus of course you're only going 6 knots or so

[Dimitri-2000X-Tampa]

I think the safest way to take waves is head-on or within 30 degrees of head-on. Less safe but more fun is to run with the waves at about 30 degrees off the stern. This is usually the best way to "surf" the boat but it does seem hard on the rudders, perhaps the CB as well.

[dclark]

At about 15mph heading into the waves with a strong wind, the boat will turn and will need immediate correction. I know the wind/wave conditions where this occurs and can anticipate it.

What are others experience with this?

I don't quite get it. I mean as soon as I hear this I think how can that be. Heading into waves and heavy winds means 5-6kts tops. 15 kts is pretty much wide open and only used when the water is fairly flat...

So is it just a difference in location and what waves are...

I picture the times heading out in the pacific with big waves and it goes something like this...ride up the wave, the bow passes over but still enough stern weight to keep you riding upward. Then oh say somewhere around the time the galley and back is on the water and everthing forward is hanging in the air, it's heavy enough to fall. The bow is anywhere from 5 feet or more above the water. It comes down slam hard on the water, the stern kicks up and the motor is catching nothing but air cause that loud wheeeee sound and the tach jumps to 8000 rpms.

So I say it's not possible to head into those conditions and the reason I say what is the point of having a really big motor?

[Mark Prouty]

I don't quite get it. I mean as soon as I hear this I think how can that be. Heading into waves and heavy winds means 5-6kts tops. 15 kts is pretty much wide open and only used when the water is fairly flat...

So is it just a difference in location and what waves are...

I picture the times heading out in the pacific with big waves and it goes something like this...ride up the wave, the bow passes over but still enough stern weight to keep you riding upward. Then oh say somewhere around the time the galley and back is on the water and everthing forward is hanging in the air, it's heavy enough to fall. The bow is anywhere from 5 feet or more above the water. It comes down slam hard on the water, the stern kicks up and the motor is catching nothing but air cause that loud wheeeee sound and the tach jumps to 8000 rpms.

So I say it's not possible to head into those conditions and the reason I say what is the point of having a really big motor?

A bigger motor adds an very worthwile extra powerboating dimension to the Mac experience. Wave conditions have to relativly mild to leverage the additional power capabilities.

I haven't been in waves big enough for the motor to cavitate but in certain wave conditions with a strong wind, she does seem to need steering corrections in the trough of a wave. I think this probably occurs regardless of motor size. Haven't you experienced this?

[Moe]

I think this is one of the areas in which the Mac is the worst of both worlds. The Mac isn't a heavy weather powerboat in that it has a relatively flat bottom (even the M) and very soft chines. Thus it hasn't the yaw stability of a hard-chined or even reverse chined powerboat hull. Nor does the Mac have the yaw stability of a sailboat's elongated football shaped (viewed overhead) section of hull leading to a large lower-aspect ratio keel.

The Mac depends upon its high aspect ratio centerboard and rudders for yaw stability. With no ballast and no boards (at 15 mph), you're feeling what head seas can do to yaw the hull, but you should be even more concerned with what following or quartering seas can do to it without them. If they yaw the boat enough to broach it, you're in trouble without the water ballast. And even with the boards down, you need to be extra cautious not to centerpunch the backside of a wave, when surfing down the face of the following one, if the rudders are out of the water.

Slow down, put the boards down, and fill the water ballast in heavier seas.

--
Moe

[Mark Prouty]

I think this is one of the areas in which the Mac is the worst of both worlds. The Mac isn't a heavy weather powerboat in that it has a relatively flat bottom (even the M) and very soft chines. Thus it hasn't the yaw stability of a hard-chined or even reverse chined powerboat hull. Nor does the Mac have the yaw stability of a sailboat's elongated football shaped (viewed overhead) section of hull leading to a large lower-aspect ratio keel.

The Mac depends upon its high aspect ratio centerboard and rudders for yaw stability. With no ballast and no boards (at 15 mph), you're feeling what head seas can do to yaw the hull, but you should be even more concerned with what following or quartering seas can do to it without them. If they yaw the boat enough to broach it, you're in trouble without the water ballast. And even with the boards down, you need to be extra cautious not to centerpunch the backside of a wave, when surfing down the face of the following one, if the rudders are out of the water.

Slow down, put the boards down, and fill the water ballast in heavier seas.

--
Moe

Yes! this is my observation. I feel I have been in conditions where I was pushing the boat too hard; conditions where it might have helped to fill the ballast and put the boards down but I still learning this boat. With the boards down, 5mph would be the fastest safe speed. High winds combined with the wave action can also contribute to a yaw condition.

One day yet, I'll be sailing that puppy to Hawaii.
just joking!

I agree that sailing in these conditions is often preferable but on occasion a course that puts you in this circumstance is unavoidable.

[dclark]

[quote="Mark Prouty

Haven't you experienced this?[/quote]

oh yeah.

[dclark]

[quote="Mark Prouty

Haven't you experienced this?[/quote]

oh yeah.

[Duane Dunn, Allegro]

There is a sweet spot, at least on my boat, at around 10-11 knots, no ballast, all boards up. I find that in medium rough conditions 2-3' seas, not to tightly spaced, that going slower at 8-9 knots I fight yaw and have to constantly correct the steering. It is so bad at this speed that the autopilot will frequently loose it's course. By speeding up to 10-11 knots it seems like I gain some form stability and there is a lot less steering input required. Unfortunately once the seas reach 4' this is to fast. As soon as we start launching and slamming down I slow down. We have gone through some very steep rough water with no ballast or fins at 5 knots and the boat can be a handful to steer, yet never have we felt threatened with a roll.

We had one day on the long trip where I had 4' seas from just slightly to starboard of dead astern. Keeping our speed up to the 7-8 range proved to be the most comfortable from a steering standpoint yet it was still a workout. I think no ballast and no fins is better in these heavy following seas. While having the boards down would improve tracking, I worry that the heavy side loads on them would break something.

We never run at WOT when out cruising. It uses too much fuel and is to noisy. If we are in a hurry to go a short distance we might open it up to 14 knots for a brief time only.

The only time we use WOT is when out playing with water toys. We were out in some medium rough water with the toys on Labor day. We used the tube, knee board and the water skis. I would be searching out the biggest wakes to swing the boys through on the tube. The boat sliced through with no problems, I'd throw the wheel full over to do donuts and rough things up even more. The boats loves this with no stability issues. We had 6 on board, no ballast, no fins down. We did have to alter our normal approach to bringing the ski rope to someone as the boat makes to big of a circle for the circling method. We had to use the flyby with a tail kick method. I'll post some pictures in another post.

[Dimitri-2000X-Tampa]

You can put some of the CB down at higher speeds, like the 6 inch down position frequently used for docking. It will also work at higher speeds to give the boat a bit of a "skeg" and I don't think it is too much load on the board in that mostly horizontal position. I've done this up to about 10-11 mph with good results. In heavy seas, I will put out a bit of sail (usually a bit of headsail) also and then power slowly (4-6 mph) with the motor. The motor is enough of a rudder and the sail gives the boat better roll stability. I believe the term is motor sailing and it seems to be the most comfortable on the crew when the weather is rough.

[Frank C]

.... Yes! this is my observation. I feel I have been in conditions where I was pushing the boat too hard; conditions where it might have helped to fill the ballast and put the boards down but I still learning this boat. With the boards down, 5mph would be the fastest safe speed.
.... High winds combined with the wave action can also contribute to a yaw condition.
.... I agree that sailing in these conditions is often preferable but on occasion a course that puts you in this circumstance is unavoidable.

True enough, all three comments! Things to always keep in mind though:

• - boards only if sailing (or < six knots which is sailing speed). As Dimitri said, about 6 inches of CB is fine as a skeg
  - I think if motoring at such a low speed, might as well have a swatch of canvas for its roll stability.
  - But in any kind of wind waves, ballast at any motoring speed (say >9 knots) will create LOTS of spray across the bow. If you're intent on exceeding sailing speed, ballast is heavier, more costly, and a much wetter ride ... granting tho, that I don't have a dodger.