Hull/Speed dynamics of Camano/Helmsman

[Nomad Willy]

Greg S wrote;
“NB: CH 31 is only 31 feet for bragging rights. Hull overall is 28.”

28’ hull. What is the beam?
Could the hull’s aspect ratio be extreme?
I notice the above poster experiences high speed turning is w “minimal lean”. I’ve observed a small irregularity that I think is small areas of the bottom corners that have a small down-turn of the hull.
If so that would make a low aspect ratio boat that usually does turns on plane w a rather flat attitude (minimal lean) turn even flatter. It’s certainly predictable and normal for the type and perhaps even more prone to turn w a flat attitude w a bit of hook in the hull corners. Because the outboard hull corners may likely be out of the water whereas the inboard corners would be well submerged.

 

[Greg S]

28’ hull. What is the beam?

I notice the above poster experiences high speed turning is w “minimal lean”. I’ve observed a small irregularity that I think is small areas of the bottom corners that have a small down-turn of the hull.
If so that would make a low aspect ratio boat that usually does turns on plane w a rather flat attitude (minimal lean) turn even flatter. It’s certainly predictable and normal for the type and perhaps even more prone to turn w a flat attitude w a bit of hook in the hull corners. Because the outboard hull corners may likely be out of the water whereas the inboard corners would be well submerged.

Width 10.5 feet. Call it 10 feet at the waterline.

Yes, turns pretty flat. I don't recall it leaning on a turn but also wasn't going fast very often. (Fast? 14 knots) generally the only time I went much over hull speed was in rough water to take advantage of the dynamic stability.The boat never seemed to climb up the bow wave, it just pretty much kept the same attitude and accelerated until you ran out of throttle at about 15.

 

[Jeff F]

That gives me an idea... For anything with a deep enough keel to protect the props (think Grand Banks), if you've got stabilizers, why doesn't someone make them strong enough to hold the boat up and ideally extendable? Want to clean the bottom? Let the tide go out and leave you aground, extend the stabilizers down as legs to keep the boat from falling over, then get to cleaning.



Other than the complexity of the legs and the need to have a deep enough keel, that would let you do this with whatever hull form you otherwise want (rather than making sacrifices in other ways to gain the ability to ground it safely).

Google "beaching legs." They're common in some areas.

 

[Jeff F]

If so that would make a low aspect ratio boat that usually does turns on plane w a rather flat attitude (minimal lean) turn even flatter. It’s certainly predictable and normal for the type and perhaps even more prone to turn w a flat attitude w a bit of hook in the hull corners. Because the outboard hull corners may likely be out of the water whereas the inboard corners would be well submerged.

My Mainship 34 leaned out in high speed turns. Felt weird.