Hulls uneven waterline ?

[Gboy]

Dry hulls, balanced weight distribution but one hull sits 2 inches lower in the water than the other.
Ideas ??

Thanks for feedback.


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[MBWhite]

Is this on a 47 foot boat or something smaller? If it is a 47 foot hull you are looking at a serious amount of weight somewhere. Are you planning on hauling it out of the water for the winter?

Also, if it was bought at a gov't/coast guard auction start poking around for an extra ton of pot hidden in the hull somewhere.

[Ex-Calif]

Measure from the deck to the bootstripes
Measure from the deck to the water

If you have confirmed those measurements Archimedes will tell you the weight in the hulls is not balanced.

Or one hull is smaller than the other.

[Gboy]

I measured the stern bottom to waterline. Paint lines etc are equal. No extra weight on the lower side.
It takes about ~500 Ibs to equalize on opposite higher side (3 guys).
This is a narrow hull CAT.
Don't think I could take on much water in the hull wall, it's a honey comb resign structure... No visible issues on hull... Changed out the rudder on that side .. But same design.
Maybe just the way the boat was constructed ?


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[Gboy]

By the way only on one stern, bows equal.



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[colemj]

Was this boat ever stretched out in length from a previous model (even by the factory)? If so, they may not have got the run of the stern rocker even on both, or may have put a slight bustle in one (or both). When on the hard and sitting so that you know the ground is flat and even, measure from the ground to the bottom of the stern. Alternately, take stationed measurements from ground to boat starting from somewhere in the middle of the boat (back of keel/board) to the stern. See if those measurements are the same (relatively) for each hull.

Mark

[Delancey]

Nice lookin boat.

[barnakiel]

The hulls are different weight hence different displacement.

b.

[Blue Stocking]

Boat may be diagonally twisted. Set up bow and stern points, level and at same height. pick up each corner a measured amount and see if the other similar point raises the same amount. Standard test for lightweight racing cats such as Tornado and Nacra.

[mikereed100]

If the bows are at the same level but there is 2" difference in the sterns and you have confirmed that the distance from the hull/deck seam to the waterline is equal, then there is some twist in the boat. Although unlikely, have you checked the rig tension?

The next time the boat is out of the water, try leveling it with jacks and a water level. This will tell you if there is twist between the hulls. In the meantime, check the hulls for water content with a moisture meter. If the honeycomb is the scored variety it can hold a surprising amount of water without de-lamination and the ingress point(s) can be a long way from where it accumulates.

[ironhorserider2]

Are you taking into consideration battery placement? Tanks, etc?

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[Stumble]

I can only think of a couple of things it could be...

1) the hulls aren't symetrical. This is a pretty low likelyhood but could be
2) the hulls aren't attached the same way to the cross beams. Again this would be very very strange but could happen
3) there is some weight you aren't accounting for. Holding tanks, fuel tanks, and anchor chain are the first things that come to mind... House batteries, galley, hidden drugs... Something has to be throwing the weight off to one side.

My first thought assuming the tanks are full is if the anchor chain is stored in one hull? If so the far aft corner from the chain would lift to compensate. But I wouldn't have thought that much, and I would have expected the hulls to be different as well.

[travellerw]

I just read a post on a Facebook owners forum where the owner had the exact same problem..

Turned out a forward crush bulkhead was filled with water in one hull. The bulkhead was smaller than I imagined and I wouldn't have thought that much water could be in there. He drilled a hole to drain the water out and voila the hulls were equal.

Maybe look closely if you have crush compartments.

[pedro b]

Had a similar problem. In the large V gusset between hull and bridge deck rain water somehow got in on port side. Drilled a small hole and drained out a large volume of fresh water. No more water comes out during rain or wash down so must have during a major refit in boat yard.

[GordMay]

Greetings and welcome aboard the CF, pedro b.