Wow, a lot of good information on here. I see both sides.. I really do. My primary reason for going with a gopro was I didn't want to sink $2k + into a rig to take videos to show people back home. I'm not trying out for nat geo and when the guy said I would have to drop another $1,500 on lights on a system that has probably $500 or so in it didn't make a lot of sense.
Maybe I should just throw a couple of intova lights on for $120 and see if that doesn't help in a little deeper water. Maybe something like this?
Amazon.com: Tovatec Mini Torch Flashlight: Sports & Outdoors
220 lumens are not good for anything you need at least a twin 800 lumens to make any difference at depth with those intova you could at best do some macro with another camera but not with the gopro that is not good at that
I have one of those Epoque World : products-LED photolight EL-1000L HP A105 1000 lumens 105 degrees (not really 105 to be honest and probably more 800 than 1000) they cost around $250 here in UK am sure in US with less sales tax will be less. With two of those and arms you spend $600 and have some results they are not that heavy either
However in the space of 3 feet in daylight the effect is gone anyway even with 2000 lumens total