Displacement ?

[CaptMac]

My question is what is the dry weight of my boat.
The advertised displacement is 5200#, but they made both an inboard and outboard.
When they say displacement does that include the engine, tankage water, gear, people?
Is this the designed weight for all of the above?
What is true displacement or is there different types of displacement like:
Dry Displacement
Cruising Displacement
Designed Displacement

I tried to do a site search on this but still am confused

[CharlieJ]

Usually design disp is with half full tanks but otherwise empty boat.

Our boat's spec'd disp is 5300# but loade for cruising we figure her at 7500.

The only REAL way to know is to weigh the boat. Pretty easy if it's on a trailer, not so simple otherwise.

I worked up that loaded disp by adding up all the stuff we have aboard-  outboard, fuel, water,  anchors and rodes, food, etc. It's probably low ;) We're hauled at the moment doing the bottom and we're raising the water line. Again!! ;D

But yeah, there are different figures for disp- dry, loaded, etc. But bottom line- disp is the weight of water the boat displaces when afloat. More load, more water displaced. Too much load- boat goes past water weight point- and sinks :o

[Auspicious]

But yeah, there are different figures for disp- dry, loaded, etc. But bottom line- disp is the weight of water the boat displaces when afloat. More load, more water displaced. Too much load- boat goes past water weight point- and sinks :o

Just to make it more interesting, the maximum rated displacement changes with tropical and arctic waters, and between salt and fresh. Look up Plimsoll mark for more than you care to know. It's of limited impact to recreational boats.

There isn't any standard for what is in the displacement number from various manufacturers, although most are internally consistent.

Most travel lifts have a weight gauge although they aren't well calibrated. It should be within a couple of hundred pounds.

[CaptMac]

Thanks for the info, Charlie just wondering how much you have to raise the water line to displace 7500# on your boat

[CharlieJ]

Originally we had a boot top, so we raised it to the top of that- about 2 inches. Turned out that was ok in the bow, but too low aft. So this time wenraised it aft maybe 2 1/2 more inches. Tehani really didn't sit on that line, but water splashed up and made green slime on the hull topsides. Now that should be at a stop.
Besides- cruising boats shouldn't have boot stripes- they are ALWAYS overloaded :D


According to specs, it should take close to 500 pounds to make her sit one inch lower. There's a website that has that info. A calc site where you can compare boats. Don't have a link on this IPhone- maybe someone does.

[Captain Smollett]

There's a website that has that info. A calc site where you can compare boats. Don't have a link on this IPhone- maybe someone does.

http://image-ination.com/sailcalc.html

The pounds per inch spec is given.