This is easy.
I do a lot of sailing and boating. The answer to this is the Surefire A2. You have the LEDs for checking around the boat and preserving night vision (especially if you get RED LEDs). The incandescent + regulation gives you consistent throw and brightness for spotting marks, checking out the top of the mast, seeing down into the water from the deck etc...
I have both the red and the white. I use the RED almost exclusively on the boat since it really preserves night vision when you are working around the boat at night. The white is great for all other non boat experiences and seems to me to be brighter.
Just for example, I used mine down in the caribbean a few weeks ago in a dinghy trying to find the channel out to where we were anchored. Since there was a reef to the left and a dogleg of cans that had to be navigated, the A2 was perfect. It had the throw to light up the cans, especially with their reflective markings, it had the brightness to see into the water for rudimentary depth info.
I have also used mine on my 15' Whaler in 4' waves looking for a narrow channel with shoals extending out from shore (channel location is critical). The A2 worked great.
The other thing that is really a great attribute to the A2 is the tightness of its incandescent beam. IMHO for a boat light, you do not want a lot of side spill close for close in distances since this reflects off the boat and the reflection can knock out your night vision. But with the tight A2 beam, it throws out there well with very little sidespill off the light. That means you can use the incandescent for finding objects out there a ways WITHOUT wrecking your night vision. This is the first handheld light that I have seen that lets you do this.
The LED lighting of the A2 is of the nature of a floodlamp. It lights up a nice area for working close at hand is plenty bright enough. I would think it is not that far off from a KL1 in brightness. I have a KL3 and it seems like it is about 60% as bright as the KL3. That is way more than enough light (maybe even too much) if your eyes are dark adapted (as they should be if you are boating at night). I use mine a lot and I probably haven't replaced the batteries once every 2 months. The LEDs are useful for almost everything and they have a good long runtime on 2 123's. I only wind up using the incandescent in short bursts so it isn't too battery hungry when used on that duty cycle.
IMHO, features like SOS are not needed - if they are you have much bigger problems than your flashlight. The unit has to be rugged and have some measure of water resistance. It has to be heavily reliable since when you need it, you really need it.
J