MacGregorSailors.com

HI TO ALL long time reader in here and finally a owner

This is my first post, we own a 77 VN23

there is no floatation what so ever in the boat so im planing to use tire tubes



ITS A GOOD IDEA?

How are you going to hold them in place to keep them from floating away as the boat sinks? How do you intend to make sure they are always inflated and not subject to punctures from hull fiberglass scraps?

Personally, I do not think this is a good idea. Closed cell foam is the standard - can consider expanding foam but that can cause problems with access to spaces later.

Foam is much easier to work with, you can cut it ti fit the spaces available to give you maximum impact, tubes would be a huge waste of space, they are round so cant interlock and have a hole on the middle, so floatation for space would be reduced using tubes.

Are you planning on sinking the boat? All the boats I've owned before were sinkable.
Honestly, it's hard to get a hole in one of these things. If you did, I would put more faith in a life vest and handheld VHF.

Nevertheless, if you insist on an "unsinkable" boat, I would use standard Styrofoam.

I have heard of people using swim noodles for flotation. They are cheap, easy to cram in tight places, and don't shed little bits of styrofoam all over the place.

Welcome taZ-n-Izzy, beautiful boat btw, I sure wish I could have found that model. I love the lines of the 23 have fun with her. Take the advise with the foam and try to find the same type of blocks. I was missing some on my 22 and tried the type you get when you buy electronics for packing and it eventually starts coming apart and makes a mess. I just happen to get lucky and found blocks of it on the shoreline that came out from under docks at our lake. Luckily with our swing keels we can get right up to shore! The noodles could be an option till you get the right stuff so that was good advise.

I doubt you can put enought foam in it to keep it from sinking. (without taking up a lot of room) You are not water balasted.

First off, to see how feasible it would be I would roughly calculate how much volume of flotation media (air, foam) you would need to keep it from sinking, because any less than that will obviously not accomplish what you want. So calculate the volume of water that weighs the same as your boat when dry.

@ 2.2 pounds per litre, divide the weight of the boat in lbs by 2.2 and that's the volume you need, plus a bit, in litres, less in salt water. (A litre is 10cm X 10 cm X 10 cm).
As a reference, an inner tube is a torus; approx. 50 litres in volume by my estimate. So if your boat weighs, say 4000 lbs, you will need 36 inner tubes*. (4000/ 2.2 / 50 ) Or the equivalent, neglecting lots of other things.

Does that volume seem feasible when you plug in your actual boat's weight?

-B.

*If you equip your boat with explosive bolts on the keel you will need fewer.

But you forgot to add the weight of the tubes onto the boat weight, so better make that 40 tubes

Gets the tubes for the tires big airplanes uses - 777, etc. Like those kids in them Chevys - big rear wheels, look like they are always going down hill.

sailboatmike wrote:But you forgot to add the weight of the tubes onto the boat weight, so better make that 40 tubes

Or you could get 100 air bags. they would not take as much space. When it starts to sink set them off!
(Insurance may be less expensive)

dlandersson wrote: Like those kids in them Chevys - big rear wheels, look like they are always going down hill.

Bill Cosby is here ???

seahouse wrote:*If you equip your boat with explosive bolts on the keel you will need fewer.

Absolutely brilliant.

or fill the boat with these auto inflating life vests.


With all the talk of flotation to keep boats floating, you'd think these Macs are constantly capsized or holed.
It's a boat, don't put a hole in it or tip it over and you'll be fine.

Never substitute real PFDs and safety gear for the assumption that your boat won't sink.

RobertB wrote:How are you going to hold them in place to keep them from floating away as the boat sinks?

Remember its a VN23 not a M26, under the cockpit there is a lot of wasted space that where occupied by those missing foam blocks, my idea its get two 185/70 tubes for the sides and one or two 315/70R16 (hummer size tire) under there. it also provide support for the upper deck of the cockpit... the other thing its that here in Puerto Rico if i don't find this foam on the trash, its really expensive

RobertB wrote:How do you intend to make sure they are always inflated and not subject to punctures from hull fiberglass scraps?

try luck?

sailboatmike wrote:Foam is much easier to work with, you can cut it ti fit the spaces available to give you maximum impact, tubes would be a huge waste of space, they are round so cant interlock and have a hole on the middle, so floatation for space would be reduced using tubes.

will take that on mind