having a problem keeping afloat in strong tide waters

[Cgboylan]

we have a 27' Catalina, in the chesapeake bay. After a great day of sailing we were motering up the river against a wicked tide. Im not sure what was going on, there was no water anywhere in the boat, but the stern was sitting real low in the water 6"-8" unter the water line with the exhaust pipe fully under water. it almost felt like we were dragging something. this never happened before and after pulling in at the marina out of the current we began to float normal again. anyone ever have a problem like this?

[hellosailor]

All displacement hulls will "squat" in the water if the boat speed gets too high. This is a limiting factor for displacement hull boat speed. If the net speed against the fast current was more than your nominal hull speed--that could be all it took.

The same squatting was blamed as the reason why the QE2 hit a rock off Massachusetts (Martha's Vineyard?) some years ago, they were moving fast enough to make the stern squat below their normal waterline.

6-8" sounds extreme...something to keep an eye on.

[philsboat]

The faster you motor the more the stern squats down because you are getting near hull speed and your bow wave extends almost to the stern.This gives you less buoyancy in the center of the boat where the wave is the lowest.The only way to change this is to go fast enough to plane the boat and get on top of the bow wave(99% of sailboats won't do this).
The Qe 2 once hit a shoal coming into New york because it was going fast enough to drop the stern below its normal draft.
Phil

[Faster]

This can happen to any boat that has ample horsepower, and is often made worse by more people in the cockpit that what may be normal. The separation of bow and stern waves mentioned above contributes too, of course.

There are anecdotal tales of this effects' extreme results.. it is said that some of the smaller old sailing ships, piling on sail to escape persuing pirates or privateers forced the ship low enough in the water as they pushed the limits of their displacement hull speeds that they foundered.

Doubtful that you'll be able to to the same, but move some crew forward on the boat if you're concerned and you may see an improvement, esp on a smaller boat such as yours.

[Cgboylan]

thinks for the tips. i dont think the ship was over loaded, there was only tow of us, however i did notice if i went to the bow it would even out just a little bit

[badsanta]

I was on a friends boat where we noticed the same thing. We found that either with more people on the stern or rough weather we found that the PO had plumbed the bildge discharge to the sink drain. We found that if the stern was any lower than normal, the water would backfill through the sink drain into the bildge and that the buildge pump was not automatic. lucky not to have sunk the boat.