I'm among those who suggest getting yourself to a good Marine Store, like WEST MARINE. There you will find gimballed drink holders, heavy bell shaped mugs with lids & no skid bottoms, all kinds of options. Boaters are every bit as much gadget phreaks as car guys..
And if you wish to carry a length of STRONG tow rope instead of chain? Don't forget to look at the Yacht braid, as used on sailboats. Has to be the stongest rope for it's diameter you can buy...