These lights are a nice 5000K temperature and on the specifications paper that comes with the lights, states that they're over 400 Lumens each so they throw a nice circle around the back of the swim platform. Nothing too fancy, in the brackish water I swim in, you might get about a 7-10' radius...In crystal clear water, I'd anticipate an easy reach of 15-20'. Highly recommend these lights if you don't want to have any run-ins with the coast guard or sheriff for having red or green lights anywhere else other than the bow and they're also cracking down on blue lights as those are the lights reserved for the water patrol officers.
THEY WORK FINE BUT WAS NOT AS BRIGHT AS THOUGHT THEY WOULD BE
These are great! I installed two on my houseboat and they light up a very large area.
Just the look I was looking for in the rear of the boat.