would someone mind simply explaining how a boats deadrise effects how a boat rides(how stable etc...). here's the situation - it's time for a bigger boat. i've got a 20' cc bay boat, a growing family, and a wife that needs a toilet every 27 minutes. it's time to do some research. thanks paul

Deadrise is the angle that the hull makes in relation to the water. The sharper the angle the better the boat will ride in a sea. The trade off is that if the angle is too sharp the boat will roll severly in a beam sea. The angle of the chines will affect how sharply a boat will roll in a beam sea, the closer to 90 degrees that the chines ride in relation tot he water the less the boat will roll. Any more than thet gets us into Marine architecture.

I think I can help you. (I work in the field of ship design (marine hydrodynamics specifically)) As MM said, deadrise is the angle of the V on your hull. More deadrise =deeper V= softer ride in waves. For example a Regulator has about 24 deg of deadrise at the transom, this is a considered a deep V hull and it handels the chop nicely. The old Boston Whalers were nearly flat bottoms and were back breakers. (They adopted deep deadrise hulls nowadays) Most boats have variable deadrise, steep in the bow to deal with waves and flattening in the stern to help with the roll. Depending on the hullform, the roll issue can be delt with with with subtle design line mods. IMO around here the more deadrise the better, but you will pay for this with added fuel costs and deeper draft. The most efficient planing hull is a flat plate. However a flat plate rides like hell in a chop. So, basically, deadrise helps soften the ride in waves. I would not be so concerned about the roll issue as most boats flatten out the stern lines near the chines and this provides a lot of roll damping and a clean separation line.

Hope this helps.

i could not ask for 2 better answers. thank you mm and sandman. would either of you care to make a reccomendation on a boat ? here are the details - 40K budget, want to be able to make runs to stellwagen and race pt (from boston area) and not worry if it gets a little sloppy on the ride home, i'm thinking 23/25', maybe a walkaround. thanks, paul

That is a personal pefrence question. What works for me might not do it for you. Also, it depends on the deal you get. For this budget, if you have the time and energy, I would look for a great deal this fall and winter in Florida. Right now the sunshine state is loaded with a glut of used boats. Many are having problems getting insurance for boats and want to unload them. I know of several guys that have made the trip to Florida to get a great deal on a boat and bring it up north. Look around, you will find what you like.

With fuel near 4 bucks per gallon, you might consider something with a diesel that is a little slower too. Some ballpark numbers to think about:
A 32' CC with twin 300's burns 35gals/hour at cruise. A 27' CC with twin 225's burns about 20 gals/hour (or more) at cruise. A 23'er with a single burns about 12-14 at cruise. A 21'er with a 140 will burn around 8 or 9/hour. A 27' single diesel is in the 5 gal per hour area with a slightly slower crusise but about 3-5X the life of a OB. (I know there are exceptions to all these but this is about the norm)

My only advice is to avoid gas inboards, you will reget it and convert. I think a lot more boats will be on the market this winter. People are fet up with fuel costs. (The guy at the gas pump told me he is selling a lot less fuel this season)