I need to head down to the boat and measure the current unit and figure out max dimensions for the space available. The current setup is for just what you described and Todd Dunn seems to be happy with his. The only down side to the current setup is that in order to get to the contents you need to unlatch the door, pull the bolt for the shelf, slide the entire unit out and unlock the top to get the lid open. Or, you can shortcut, leave the locker unlocked, the bolt disengaged and it will empty itself out on a port tack?