This is the tool box I have stored our Yanmar engine spares in, it measures 16″ long x 8 1/2″ deep x 10″ high.
It contains 2 Racor filter elements, 1 Yanmar fuel filter, 1 oil filter, 1 spare remote starter relay, 1 raw water pump impeller, and spare V belt. Also included is the small wrench set Yanmar supplies, my wrenches and extra sparkplug for my outboard motor and right now a lot of empty space for other essentials.
All of the above used to be stored under one of the settees and took up the space of about two dozen cans of beer!
View looking into the inside of companionway steps from out in the cockpit.
To mount the box under the companionway steps all you need is a bracket and strap tie down set for an outboard fuel tank, cost about $5.00! This is pointed out by the blue arrow, the red arrow denotes a short piece of aluminum angle I added to keep the box from ever moving side ways.
Supplied by Bill Martinelli Voyager #11