Weight vs speed
 

Hi!

I have a 25 feet Phantom offshore hull. According to the builder it was built extra solid (and heavy..). The current weight is approx. 1150 kilos incl. engine less driver.

Below the front deck you will find a inner floor between the stringers running from the bow to the aft of the boat. It is made of approx. 15 mm plywood. I addition to this the cockpit floor is 25 mm, and runs from 1 meter in front of the dash to the fueltank aft.

In all those two "floors" add some kilo of wood. I plan to cut out the 15 mm plate between the stringers, since the weight in front will be less. The wooden cockpit floor will be replaced with a light weight floor. Maybe divinycell? Other suggestions?

The boat runs very flat and require positive trim. I expect less weight in front of the balance point to be approx. 70 kilos. How much speed will be gained ...??

Cheeeers and thanks, Toffen G - Norway

Id like to know what this weight reduction would do also as im loosing a lot of weight in my 40'. I am still trying to do the conversions from mm to inches.:D

Toffen Try the speed calculator at bam marine site. Plug in your know numbers and the reduce the weight.

weight vs speed
 

Hi!

I checked Go Fast speed calculator, and I gained 2 mph when the weight is reduced with 50 kilos. I gained 3 mph when the weight is reduced with 75 kilos. The main goal is to reduce the weigt in front., making it easier to lift the bow (+ less weight overall too).

Cheeeers and thanks, Toffen G

What the H*ll is a Kilo ??????

Some of us never changed !!:D :D

Toffen,

Sounds like allot of work just for a couple MPH, also once you start cutting it up you will really depreciate the value, something to think about.

WILL:p

Geeezze guys... don't know anything metric? one Kilo (kilogram) is 2.2 pounds... one inch is 25.4 mm. one meter is a little more than 3 feet...a liter of gas is a little more than a quart... so ... when he says his floor is 25 mm thick... it's probably one inch ply... as they say " America is going metric .... an inch at a time "........:eureka:

Toffen... if you have a boat that size... and it only weighs 1150 kilos including the engine... I wouldn't say that it is really all that heavy.... I'd leave it alone.