Some of mine you push on a "rocker" in the deck fill cap and it rocks up a twist handle. Others will open with a winch handle.

Depends on the type of cap. If it has two holes in the top, you can get a device from any marine store that fits into the holes and acts as a handle. When really tight, I use my Leatherman pliers, put the tips in the holes and twist. Some caps use the winch handle... if the cap has a hole on top that looks like the top of the winch, use your winch handle.

The 1999 model came with the metal filler cap which uses a "key" which has two holes and a wide slot. West Marine has a universal style metal key which fits it perfectly and has a bit more leverage and grip than the small original ones which came with the boat.

[url]http://www.westmarine.com/deck-fills/davis-instruments--universal-deck-p...

Here is what the original looks like only metal [url]http://www.westmarine.com/deck-fills/perko--plastic-deck-key-fits-1-1-4-... Correction - the original was all metal, but did not include the handle part, just a smaller part with a small grip area above the two points.

Any marine store will sell the special tool, but I generally prefer to use a pair of needle-nosed pliers anyways.

Why 2, you'll never, ever, not even once, drop one overboard :p