Masthead floats for cruisers?

[valhalla360]

What do you mean by "small". Beach cats...sure, they might flip a couple times an hour.

Cruising cats don't flip very often and then it can usually be traced to doing something dumb.

The mast failing is possible but far from a sure thing. If it's strong enough to lift a hull (kind of necessity for flipping), it will depend on how much momentum it has when the mast hits the water. I'm betting most masts stay on but not a sure thing either.

I recall reading in Chris White's book that to right a small cat they could do it with a dingy and a 15hp engine. You ran lines back to strong points at the stern and pulled forward. The drag would cause the bow to go down and eventually flip end over end. No idea if it really works as we've never been close to flipping. Plus that assumes you can right the dingy and get the outboard going.

It's fun theoretical exercise but not real practical.

[Sailmonkey]

Everything about masthead floats is here.....it may be scalable but we’ll still laugh at it.

hobie bob

https://www.google.com/search?q=hobi...iw=320&bih=454

[belizesailor]

A simple float like on a beach cat of course would be inadequate. You would need a substantial lift bag just to get the mast head back up to water level. Then what?

With beach cats its common to use body weight, sometimes aided by a water bag to right the boat. The righting moment on a larger cat is huge so scaling this concept up would be problematic.

Carrying all this big bulky gear along for the unlikely capsize event I think would be impractical.

[boatman61]

Flipping a cruising cat is different to flipping a Hobie beach cat.. weight for a start.. the masts are designed to take mainly downward loads.. hence sitting on the keel or having strengthening mast supports if deck mounted.
Take into account the side loads not to mention forwards momentum as one presumes the cat will be travelling when the event happens I would say 9 out of 10 masts will fail and that includes mono's.. knockdowns are something else.
Rollovers or pitch poles on mono's rarely come up with mast intact, the exception being if hove to with minimum sail up.
Saving the hull is feasible.. but by relying on the mast, in anything but the most benign sea's is not

[thinwater]

A factor that several hinted at but did not clarify is that adding weight and windage at the masthead increases the chance of capsize signifgantly. Floats are very rare because in the opinion of the designers, this increased risk is signifigant in smallr boats and outweighs any theoretical benifit in larger boats.

It cuts that thin. The float or inflatable unit makes more likely that you will flip. Forget that. Expend the same engineering effort making a more stable boat.

[Dougtiff]

I remember way back many year's ago reading a book by Rudy Cheoy, a hawaiian Cat designer, he was playing around with mast head flotation and it seems like i remember reading about flipping multi hulls back up by flooding the back end and and righting her endo not side ways.

[ZULU40]

Originally Posted by Dougtiff

I remember way back many year's ago reading a book by Rudy Cheoy, a hawaiian Cat designer, he was playing around with mast head flotation and it seems like i remember reading about flipping multi hulls back up by flooding the back end and and righting her endo not side ways.

presumably not something to be attempted in the conditions that sent her over in the first place. Which goes to the well made point about keeping the hulls afloat and surviving on the upturned bridgedeck or within the hulls.

Having achieved that deliberately sinking the remaining half of it, well thats for those braver than me ...

[Cadence]

Originally Posted by ZULU40

presumably not something to be attempted in the conditions that sent her over in the first place. Which goes to the well made point about keeping the hulls afloat and surviving on the upturned bridgedeck or within the hulls.

Having achieved that deliberately sinking the remaining half of it, well thats for those braver than me ...

[catsketcher]

Gday Zulu

That recollection may be incorrect. I just looked up Choy's book and there are no accounts of masthead floats there or in his article in the capsize book. Interesting though what he did write about capsize - one quote -

"the most paramount reason for capsizes arise from crew failure. Lack of seamanship, ignorance, carelessness, fatigue, poor judgement, and muddled command are weaknesses to be overcome."

There are more insights in both books (including his article in the Capsize Bugaboo). Maybe you read an article in Multihulls magazine edited by Charles Chiodi. I have lots of them but don't read them nowadays. It makes me nostalgic for the days when people built their own.

cheers

Phil

[Delafontaine]

Kenton, please read carefully the replies, Palarran said 'use the google custom search' - - this is NOT the simple search function !
if you follow this good advice, you will find this old thread

http://www.cruisersforum.com/forums/...ml#post2059559
and on post No 139, my photo of one Iroquois in Brightlingsea, with an excellent float, a very good design from 50 years ago, by Rod Macalpine-Downie .