I have experimented with a few different varieties over the years starting with halogen before LED even existed and they all have worked well. One thing I have learned is it is nice to have lots of lumens however those do get cost prohibitive if you are looking at some of the brand names and to be honest with you, a huge ripoff for what one gets. I just built some new ones for installation next spring. They have threaded holes in the base which will be secured with 2 SS bolts to the top of the trim tabs. 2 will point directly behind and 2, 45º to each side. Used 50w cob leds which I set into a custom machined housing and encased them in resin. made 4 of them which equates to a total of 200watts of led light or about 16,000 lumens if you prefer. Used these which are 12v so no special transformers or driver required. https://www.aliexpress.com/item/50W-COB ... -cQAvD_BwE

Waterproof T connectors so I end up with a single wire going through the transom to supply power. They are a little better than an inch thick and 5" in diameter. Should illuminate the depths quite well to say the least. Total cost is under $100 for all 4 however I do have access to a machine shop so the machining is free.