240 THOMPSON BOTTOM DEADRISE

[newtoboat101]

Hello, would anybody know the deadrise of bottom of boat 1988 thompson 240, looking to put raymarine real vision 3d thru hull transducer,but not sure which one is correct for my application,any help appreciated

 

[mr 88]

Usually you only have 2 , degree options , with the ducer . The only way to do it properly is to locate the area where you're going to install it and use your cell after downloading a app for it . Might have to Google something like app for leveling or measuring degrees . Protractor or whatever it's called that the welders use for measuring angles may also work . Pretty sure it's about 19* but it changes as you move towards the bow .

 

[JimS123]

A straight edge and a ruler. Oliver has a heap of apples. Tan(deadrise) = O/A. Easy peasy.

(with all that crap I learned in High School, it's a wonder I can think at all)

 

[Scott Danforth]

Can also use a level app on the phone

 

[newtoboat101]

thanx all, found angle app on phone ,worked great thank you for your help everyone

 

[newtoboat101]

so i used the angle app on android ,well my boat was not totally level so one side measured 10 degrees and other side read 17 degrees ,should i split the difference and call it 13.5 degrees ,what im trying to figure out is what angle raymarine thru hull real vision 3d ,what do you all think

 

[JimS123]

Ignore the bubble since the boat is crooked. Align the device so it's level with the boat's waterline, not the ground.

 

[mr 88]

How critical can it be , the hull is always moving side to side . Not like a ducer , that you're trying to mark the rigger weights with . More of a guideline for optimal conditions . What are the choices you have for the ducer deadrises ?

 

[JimS123]

How critical can it be...... What are the choices you have for the ducer deadrises ?

Do the high school geometry math! It's not rocket science.

If you are off a few degrees and in 20 foot water, the error will be minimal. If you are downriggering it in 300 foot water, the error will be huge, but then again, what's the difference?

My many boats over the years have had transom ducers mounted by me. Easy peasy. My current SeaRay has a keel mounted 90 degree ducer and it's awesome. But it was OEM.

Regardless, if it were me, I wouldn't even contemplate drilling a hole in the bottom of a 34 year old fiberglass boat.