Well this weekend I got some significant steps done. The cockpit locker was where the battery was initially installed. However, I always had to worry about putting stuff on top of the battery and messing with the cables. Furthermore, I am going to install a house battery in the Spring, and it would take even more storage space from the locker. Underneath the cockpit floor, however, is a ton of unused space. So I used a door cut in the locker to install a plywood base for the batteries that would hold them underneath the cockpit floor. The batteries can slide out when needed for maintenance, but otherwise will be strapped down with a luggage strap. The plywood piece that holds the batteries is held in place by aluminum L-brackets, has small wooden rails fore and aft so the batteries can't fall off, two u-bolts for the strap and a thin rubber floor to hold them tight (to prevent chafe). I tested the strap concept in my basement, and it held the battery very well.
While I was at it, the rest of the unused space was used for water storage. I put down a plywood floor, also held on with L-brackets. There are two square areas fitted to the blue water tanks I have, also with rubber floors, which will hold the tanks tight. I also have u-bolts for the straps to hold the water containers tight. I originally was going to install a proper water tank, but decided that it is probably unnecessary and a little costly to boot, considering that I can just store extra water in $10 walmart water containers and refill the existing water tank as needed. Not as convenient, but still functional and... cheap...
I also cut a hole out for a mini-fridge that a friend gave me for free (she was moving and didn't need it anymore it is nearly new). I put a floor at the bottom of the hole, and will use some fiberglass wood-colored moldings ($5 a piece at HD) to make the hole look nice. The fridge can slide out for overnights and an Igloo cooler strapped in its place. The fridge must be removed for access to the blue water tanks, but I will only be using them when ovenighting/cruising anyway and the fridge won't be installed at those times so I should have easy access by just removing the cooler.
Finally I installed some deck plates in the areas of the boat that I had no access to previously. This picture shows the cockpit locker which previously held the batteries, but now has a door into which the batteries are slid in and out of the floor I made for them.
Now I just need to finish the countertop with formica and I will be done with this part of my boat project.