Leatherman and multimeter followed by duct tape and zap straps. My boat doesn't sail without that stuff on board.
An example would be when you have to unbolt a piece of deck gear and there's no helper in sight: you can use vise grips to keep the underdeck nut from moving and can unbolt from above.Sure having and using the correct tool is the thing to do but I think Visegrips are one of the best tools ever invented and I think it would be foolish to venture off without a few sizes of them - just in case .... for whatever - They Work - when sometimes nothing else will.
dayum...While we're on the subject of drinking tools how about this one! It's my CAN CRUSHER and it really minimizes my trash volume on board.
Sorry for the picture resolution, I really had to crop in on this one, but it's the brown mechanism mounted to the left of the companionway.
CRUSHA (yes our can crusher has a name) is the bomb !!