Measure twice, cut once...a wise policy....

except on a boat its BS. Measure twice, cut four times, shave a bit off, and finally in desperation hammer into place. On a boat there are no right angles, just a lot of wrong ones. The holding tank is going in, whether it wants to or not.

The original location of the sonar from hell, ideal place to put a 13 gal holding tank.

Dry fit, looks good.

Cut the remaining liner to discover that the lip of the forward water tank (which may be removed later) gets in the way.

Lower the floor below the tank, simple, NOT.

Now to run the inlet and outlet hose.