Sandy & Bob, >We have a mid '86 version and in spite of the plans, we don't understand >the water tank (s?). Our KK42 is also an '86 model. >The starboard fill overflows rather quickly (30 minutes at our marina). That's about the time to fill one of our tanks as well. >The port fill takes twice as long to overflow - at least. Are filling it first or second? If you're filling it first (and both tank valves are open) some of the water may be spilling over to the starboard as you're filling the port one. I keep one of the tanks closed off while we're using water from the other so this can't happen in our case (excepte for a small amount that could go over through the vent line. >Taking the fill cap of the port after overflowing the starboard, it was >obviously pressurized. Errr. You don't want to let city water pressure pressurize those tanks. They're fiberglass and you could split a seam open that way. I make sure there is PLENTY of room around the fill hose so that can't happen. (I fill until I get water overflowing at the fill hose, not the vent hose, since that would require more pressure.) Of course, there's still a small pressure buildup when the neck fills all the way up (about a 2-foot head). That's probably not good either, but at least it's not the full hose pressure. >the tank vent seems to be on the starboard side and >whooshes like mad when the port fill is used. That sounds normal. The sents on the two tanks are connected together. >Are there two tanks with a very small connection? There are two separate tanks -- connected by a small vent hose and then to the outlet on the startboard side. If you go to the far end of the passageway forward and open the hatch in the floor by the door, you should see the vent connection for the port tank. If you remove the cushion from the settee in the guest stateroom and pull up the boards at the forward end, you'll see the plumbing for the vent line (headed toward the overflow/vent on the starboard side). >Is ther an undiscovered valve? What's up? I'm assuming you've found the two valves under the false floor in the guest stateroom hanging locker. They allow you to select either/both/neither tank todraw water from. I keep one always closed when cruising so I KNOW when one tank is empty. Then I can estimate how long I have to go on the other tank -- to keep track of the last tank I made a wood sounding stick (with calibration marks) to track the last drops so I don't get any surprises at the very end. I hope these ramblings help some. - Bryant