My vote is for a Gralmarine but like others have said need to be more specific what your looking for. Check out
https://www.gralmarine.com/home-en these are extremely robust expedition lights. Since these guys only do lights and have been making them forever they really know how to build a light and they make a light for what ever your need is. Check around and even with all your high priced flashy brands like halcyon, light monkey, etc. they do not offer a product anywhere close to as user chooseable (if that a word) as these guys do plus these lights are literally bomb proof they make them all the same and they come with a 150m rating but if you want they will test it to 300m for you but since there all made the same technically they are all 300m rated lights, think about how strong they have to be to withstand that pressure.
You buy a light by specifying what light head you want they have narrow beam, wide beam, video light extra wide beam, combo heads with narrow and wide beams, and all kinds of different lum's from little hand held backup 1,600 to 19,000 monsters. Then you choose what batter size you want based on run time you need. All there batteries have options for Aluminum housing or delrin, two out put ports for the heads one is regular one is 90 for sidemount and if you want to get really fancy you can hook two lights head up to you batter one on you helmet and one on your goodman.
These are also very reasonably price for what your getting.
One other thing I think I saw someone post that you should get a Nanight light. Just a heads up about these, I have some friends that did some photography/advertisement work for them so they were sent lights for demoing and they have already flooded 4 of them. They talked to Nanight and they even admitted they are having some Quality Control issues with the glue they use around the front glass to the body.
