How is deadrise measured?

[Mr__Bean]

Hello all,

Please excuse my ignorance here, but how and where is the deadrise of a boat measured.

Whilst I hear the term used frquently, I have never really understood what it means.

Thank you,

- Mr Bean

[Corpus Skipper]

The deadrise is the angle of the V on a hull, and is measured from one half of the hull's rise from keel to chine against the horizontal. (19 degrees deadrise= 19 degree angle up from horizontal) When someone mentions a boat's deadrise, they're usually talking about the angle at the transom, though deadrise can refer to the angle at any point along the hull. Most folks refer to the deadrise at the bow as the "entry".

[SeaDrive]

Most folks refer to the deadrise at the bow as the "entry".

But if someone were to say a boat has a 20 degree entry, that would be the half-angle in the horizontal plane (i.e. the angle between the waterline and the midships line), would it not?

[Corpus Skipper]

the angle between the waterline and the midships line
Are you refering to midship as in fore and aft, or the keel. If you're refering to the keel and the chine (waterline, more or less) then your statement is correct.

[Sean Herron]

Hello...

A lot of guys measure deadrise as the angle anywhere along the hull that roughly matches the flat of the hull from its main chine against a vertical thru its station lines...

Deadrise is the above - angle against the vertical thru stations - taken anywhere and in case of high speed power boats it is measured at what is some times called the ride plane or pad - the aft stations where a properly trimmed boat rides at speed...

SH.