The OP asked about relation between lumens and watts (wishing for 1 watt light) - modern 1.5 watt LED emits about 100 lumen of light. 1 watt would've been useless on 200 ft.
True, 1 hour is not much - it could be dead when you need it the most.
Also, narrow focused beam at low angle - almost from the sea level - is less useful than people might think. It's a weird lighting, making familiar surroundings look unfamiliar (and you don't see anything beyond that bright spot).
This will light up your life, it has three levels of brightness and a strobe function. I paddle 24/7...it'll light up wide rivers, illuminate possible camp sites from the water (Best use) and locate the reflective deck lines, patches & etc at HUGE distance (I've kept track of a paddler at more than a half mile with it).
I use a dummy cord from it to my PFD, attached with a mini keychain carabiner to avoid a repeat of the episode where I leaned my head back to look up and dropped it off my head "Kerplunk..."
Why a headlamp? because the light is focused where you look, and leaves your hands free to paddle, etc...
Discern is fine There are some really amazing lights these days. My bike light is effective to 200 feet and reflects off signs at something like 500 feet. “Discern” may be enough to keep you from hitting a rock.
Narrow beam I agree about the narrow focused beam. I experimented with a powerful flashlight on my bike. I think it was a Fenix. The throw was amazing, but it was too narrow to be of much use.
A headlamp is very helpful for increasing your field of vision, but still for kayaking a fairly wide flood on a headlight is very helpful. That’s why I use both lights—for throw and a wider field. (notice difference between headlamp and headlight)
$.02 lithium batteries don’t weigh as much as alkaline. Consider getting a AA flashlight, put lithiums in it then glue on some 1/8"minicell around the handle for extra flotation. If it’s not tethered and it’s not on you’re going to lose it even if it does float. Not tethering it carries the risk of it falling off your boat or out of your hands and onto hard ground while transporting it. Watts can be a reasonable comparison of power as long as you stay within one kind of emitter. Comparing 3watts LED to 3watts Halogen/Krypton bulb doesn’t work.
UnderwaterKinetics 4cell it’s not huge, can lay flat and WILL project a beam that will illuminate an object 200’ away. Not for long time burning as I suspect the heat build up is significant although they say they have a large heat sink. You can tether and dangle it off in the water to see fish come by. Any flashlight that can do what you want will cost a fair chunk of money and it would be wise to tether it as you would a VHF radio, pump or paddle float.
Although it’s tough enough to handle dropping on hard surfaces tethering it ensures you won’t lose it during rescues or other times.
one hour may be fine if just using it for a few seconds here and there to check out bits of a shoreline. Likewise being somewhat bulky may not be a big problem since such a light doesn’t need to be on the PFD. This isn’t about a primary safety light.
different speeds at 10-20mph you need some peripheral light to illuminate what might come into your path. At 0-1mph sitting in a kayak having a tight beam is what’s necessary to signal to boats far away or illuminate objects 100+feet away with limited watts
lighter batteries means less flotation needed to float the flashlight. With a AA light you have the option of Lithiums or rechargeable. I wish there was over the counter Nimh C cells. Seriously if you need it, tether it, having something float away from you isn’t much use if you need it.
securely to the kayak. It is water resistant (I dropped it in a pond one night and it sat there for 45 minutes while I went to get a fishing net to retrieve it); has great throw and spill. It has nothing to provide an anchor for a tether.
easy Buy a kayak roof mount foam block. Carve out a spot for the light and carve it to fit the contour of your deck. Then just lash it under your front deck rigging.
It doesn't meet all your needs, but you can focus it and vary the intensity to extend battery life. It is very bright when adjusted to spot and full power the 3 AAA batteries last about 1.5 hours. I mounted one of these on the front of my canoe and ran the battery pack back to a thwart that I can reach. IT works great on foggy nights.
IF your looking for a hand held light look at the UK
This light is very powerfull for it's size and the batteries last a long time.
Neither light is cheap, but in my line of work I need very good lights. There are better lights out there but most take secial sizes of batteries. I like keeping with AA and AAA sizes.
Both of these lights I use every day. I keep the headlamp attached to my hard hat and the UK light in my pocket for back up.
Ever hear of Streamlight Check out their web site streamlight.com they make a lot of different lights used by the Fire Dept, Police, & the Military. Their lights aren’t cheap but they have a great warranty. I have the Waypoint it takes 4 C batteries & has a High, low & strobe setting.
200 feet isn’t far at all. You don’t need a spotlight for that, much less the kind of spotlight that would be mounted on a small ocean-going ship. Even an old-fashioned flashlight with two D-cell batteries will light up trees and riverbanks at that range, at least enough to let you know what is “over there”. Typically, all you need is to “see” the nature of what is there. The lights I mentioned in my other post will easily light up the side of a house at 600 to 800 feet, and at 200 feet will show all the shoreline detail or obstacles in the water that an inland paddler could possibly ever need. I wouldn’t be surprised if the high-tech lights being mentioned can do the same (I just haven’t used one of them).
Comparison test: Task Force vs Coleman So I bought two lights, both crees: the Task Force 3W, 150 lumens, 2 C-cells, $24 at Lowes. (I believe this is sold only at Lowes.)
I compared them at close range and long range. The Task Force, as the reviews confirm, has an amazingly long throw, easily more than 200 feet (I’m guessing 400 ft but I didn’t have 400 feet of free space to test it due to woods) and is very bright and clear at 200’. But the beam is unusually narrow. This is quite a heavy light (10.24 oz)and not water resistant.
The Coleman can also reach 200 feet, but with only about 2/3 the brightness and clarity of the Task Force at that distance. Its beam is about twice the width of the Task Force, and the circle of light is uniform with no disturbing shadows. This light is water resistant and about half the weight of the Task Force (5.8 oz).
The Task Force is definitely a stronger flashlight, but I concluded that the Coleman would be more suitable for kayaking due to the greater width of the beam, lighter weight, acceptable clarity at 200’, AAA batteries (cheap and rechargeable) and water resistance.
It would be good to find a light that is powerful and has long throw and a wide beam, but in the $30 and less category I couldn’t find such a light. The two lights I bought seem very good for the price.