I use some Turtlelite IIs for earthquake lights. I like the fact that they are dependable and can take Li batteries and have very long runtime (web site estimates 60hrs I recall).
While I think the LW 3000 and LW 4000 look interesting, the lack of an Li option make them much less attractive to me.
Interestingly enough, if the LW 4000 was a four cell light instead of three, I would seriously consider using it with Li D cells + dummy cells. In fact, I do the equivilent of this with a 2D Maglite and 4 cell LEDcorp ProSeries LS bulb.
While I don't own one, the LW 2000 looks too cheap to put much trust in, but I could be wrong.
FWIW, the Attitude is a great little light, but the fact that it doesn't have an Li option rules it out for what I want in these particular lights.
Since you said general purpose light, I think the TL II, Attitude, LW3000/4000 seem like good selections depending on what you like.
The Attitude is nice and small, the TL II is easier to turn on and off, the LW3000/4000 should be fairly bright.
That said, you might also consider a rechargable light like the Stinger HP (I know, wrong section). In my particular case, I choose the Surefire 10X as the general purpose / work light since it's rechargable, has long runtime with the less bright bulb, and has the versitility with the brighter one. Of course I ordered them in Oct '01 and I'm still waiting.... :-(
[
I just re-read the thread and missed the boat-light intent.
While the floating aspect is nice, I suspect you are going to want more light unless this isn't your primary light. I imagine I wouldn't want to rely on the TL II or the Attitude in the dark on the water, especially if I was looking for the shore.
Something with a bit more light and a bit more throw might be in order. I would probably say the LW3000/4000 would be about minimum I would consider, but perhaps something like a Surge or Stinger HP depending on what kind of boat (and if it has an electrical system to hook up a rechargable).
And I'd probably look at the UK 2L (or a couple) for a backup light.
You might also look at getting some gearkeepers for them:
http://www.gearkeeper.com/flashlights.htm
]
-john