Deadrise

A

aholst1

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exMember
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My Santego has an 8 degree at the transom. I understand what the chines and lifting strakes do (thanks to Chapman's) but in the real world, what does deadrise angle mean to me?
 
You will get a few different answers...but in my world...the more deadrise, the deeper the V, thus the better ride in rough water. However the more the deadrise the more you rock at anchor or fishing. Also the deeper the V (deadrise) the more power you need to plane. So in theory a smaller deadrise, (i.e. like you) should plane with less power needed.

I am sure someone will have some more technical answers...but these are my thoughts.
 
You can respond in greater tech detail but AFIC "toofast" has given a complete and useful response.
 
Toofast answer is pretty much on target although i would add that it's not all about the hull shape at the transom... the bow and shape of the bottom near the bow has a huge effect on how a boat will cut thru the chop.
 
What I would add is that deadrise has an immediate effect on how the boat tracks when simply turning or going straight as well as how it tracks in following or quartering seas. The deadrise also dissipates the impact as a boat lands or cuts through the water. But as Pascal says, it is really the hull deadrise at entry that matters most and even more so it is the deadrise at the forefoot, maybe 2/3 to ¾ forward of the transom at the WL that softens the impact and is most responsible for a smooth ride in rougher conditions.

Although more stable initially a lesser deadrise does give rise to snap role or high acceleration hull movement whereas a deeper vee or rounded hull will move or role more, but with more gentle acceleration.
 
The effect of the deadrise of my boat changed dramatically after I had trim tabs installed. Big improvement!
 
From all the answers and checking the specs, I got the best of both worlds, a "modified v-warped plane design with sharp entry at the stem", to a "decreased V for efficient and fuel saving performance" Added bonus - trim tabs were standard equipment.
 
and all this time i thought deadrise is what happened to zombies after dark. go figure.
 
I just wish that duck would eat the lizard on the way to a Ducks Unlimited event.

At the risk of overposting an old advertisement, here's something that shows the cutaway views of a specific hull design that was popular in the 80's. The advertisement specifically addresses the different design aspects and what they contribute.

The ad is specific to this particular design, however it can be applied to hull design in general, specifically how the chine dampens the "pendulum effect" thatis common on deep v designs.

RWS

Trojan_DeltaConic.gif
 
I like the old Trojans, especially the International series .... but if the delta conic hull was so great, why doesn't anyone still build them? Sorry to derail the thread.
 
I thought he was going to make some joke about what happens when you take a viagra...
 
I thought Deadrise was how far you had to rise after a heavy nite of drinking on the boat to get off the floor!
 
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