Here's a small, bright, floating spotlight from Stanley.

The Stanley Floating Waterproof Spotlight is smaller than most spotlights, but it still put outs 520 lumens, generated by its five-watt LED bulb. The case is both rugged and rubberized. Stanley says it can survive a 10-foot drop. I didn't drop it from 10 feet, but I did drop it on a fiberglass deck from shoulder height and it still worked fine. I also dropped into the Hudson River. I attached a line to it, just in case, but I didn't need to. It floated with the beam facing into the water. That throws a very long shaft of light down into the water, making it easy to recover at night. A rotating switch turns the light on or off and also acts as a dimmer to save battery life. If you don't need full brightness, just rotate the switch back a bit. The FL5W10 Waterproof Spotlight has a 7.2-V rechargeable NiMH battery. Stanley says it powers the light for up to 10 hours per charge.  With both an AC and 12-volt cigarette lighter charger the suggested retail is about $60, but discounts are available if you do a web search.  I typed Stanley Waterproof Spotlight FL5W10 into Google and found it for about $48. Hang on - at Buy.com they have it for $39 + $11 shipping. I haven’t shopped at this e-tailer however:

http://www.buy.com/pr/product.aspx?sku=220950632&sellerid=34785327