Hull topsides kept to same height as as29 with deck house for standing hdrm at kitchen n bathrm only. Now to use some liberty, take that extra volume that is left over from cutting off 12" of freeboard and use it to add length (remember upto 6-1 l-b is the ideal ratio) keeping same profile, draft, and beam only downsides are a heavier boat and trying to figure out a comfortable design for the more awkward space but overall faster and much better sea boat.
Doing this most likely gives the boat a similar 180 degree recovery time since the added length increases instability upside down so you still get what Bolger claimed was the reason for adding high freeboard in the first place.
Added length for the same Beam and sectional area does no increase instability upside down.
To illustrate this point, let's imagine two three foot wide rafts.
Each raft is nothing more than a inclosed box with a 6.0 inch Draft.
The first raft is 6.0 ft long; the second one is 12 ft long.
The 12 ft raft, therefore has double the displacement of the 6.0 ft one.
Now, lets build a life guard tower, say 4.0 ft high, and put a 200 lb life guard on it.
Let's put one of these on each raft and have some malicious swimmers try to topple each raft, as the life guards snooze.
Which one do you think will flip the easiest?
Hopefully, you'd say the shorter one.
Because it has proportionately more top hamper. It has the same 200 lb life guard, as the longer boat, but half its displacement.
In the interest of fairness, let's put a second tower, complete with another 200 lb life guard, on the longer raft.
And let's go even further for fairness by assigning twice as many swimmers to topple it.
That should do the trick.
What seems to be missing from this discussion is the concept that
ultimate stability always comes at the expense of
initial stability. (except in the case of canting ballast)
If you want a boat that will recover from a 180 deg. capsize, it will automatically come with less initial stability, meaning it will be easier to knock down in the first place.
Granted, the tall sides, of the sharpies in question, provide a much better target for waves than the much lower sides of a much deeper boat, of the same Beam, Length, Displacement, and Sailing Draft. Also the base of the sail area is higher on the sharpies.
This is all true. But this subtracts from initial stability, not ultimate stability.
It is very possible for the deeper boat (of the same sailing Draft) to have less ultimate stability than the taller side sharpies. This is because its lower sides and up sloping bottom provide a poorer target for waves that might right it.
Also, it is likely to have a proportionately taller mast, which provides better dampening against self righting, initiated by wave hits.
When counting on the cabin as extra immersed buoyancy, during a capsize, one makes the implicit assumption that this cabin will not be breached in any way. If it is, it provides a handy water ballasted keel, to help keep the boat inverted.
Clearly, the deeper boat is the more seaworthy choice (certainly, while clawing off from a lee shore), but by how much depends more on its design than its inherent properties, compared to its higher sided competition.
