I've had one of these LED lanterns for about 4 years, and use it as a cockpit light. It hangs from the dodger and you can rig it on a hook, a loop of line, or it's small and light enough to hang on a zipper tab.

It's fully dimmable by holding the button and can be adjusted to a brightness level to suit you, from candle-light to quite bright. Battery life is good because it's LED but even longer if you dim it. It's also weather resistant.