Fitting it in
Since I live by the motto "Never do today that which you can put off until tomorrow,", my tank sat in the basement for several years. Other people obviously let their tanks age a bit, too, because the mentions of difficulty in installing the new tanks trickled in over the years. I couldn't understand what the problem could be, as the new tank was the same dimension as the old ones.
Sure enough, though, when I finally put the new tank in place, it was too tall. What's the difference? Well, the dimensions of the two tanks may be slightly different, and the cavity in the boat may even be slightly different, but the biggest difference seems to be that the old tank had flush fittings, as well as low-profile elbows.
What to do? I pondered. It has often occurred to me how new boat owners (speaking from my own experience) tend toward boxy shapes that are more appropriate to a land house than to a sailing vessel. On a boat, the shapes are always irregular, and something soft and pliable is better yet. Well, I don't want a soft and pliable holding tank (see Why a bladder makes a poor holding tank), but there's no reason that the tank has to be perfectly vertical. In fact, unless the boat is at rest, it won't be, most of the time, anyway.
Because of the shape of the tank, deep only on the six inboard inches, then the pickup tube is still at the bottom of the tank. And having the aft end lower than the forward end might even be an advantage.
Special thanks to Mike Lehman of Gilleleje, #505, and Jim Mennucci of Quest, #433, who blazed the trail with the Kracor tank.