OK, not strictly boat related, but a recommendation based on my own experience…
But a decent flashlight and carry it… all the time. You would not believe how handy it is. Looking behind things, under things, around things… it seems the more you have it handy, the more often you find a need to use it.
If you do decide to carry a light, I would recommend spending a little more (but not a ton) and buy a decent LED light that will last. The LED’s now are bright, last "forever" and won’t die when (not if) you drop the light.
I’ve most recently been carrying a Fenix L1T that I bought from Fenix-store.com (who I also recommend). I like a belt holster, but this is certainly small enough for your pocket. Its two levels of brightness (I rarely use the low level) and although not a extremely long distance throw, its certainly adequate for most of what I do…
Its small, runs on a single AA which you can find anywhere, and goes a LONG time of intermittant use.
If you decide to get into the flashlight world, you can feed your addiction (no, you’re not the only one that likes these things) at Candle Power Forums.
As usual, no association except as a satisfied customer!