As already stated, need good pair of polarized glasses. Now I have been doing this awhile and for a starter, cheap walmart okay, go with what they have, but a tan, grey or yellow tint. Tan/brown is best overall, grey great on clear day, yellow tint, with overcast. The clearer the water and less cloud's the better. As far as aiming, aim for the belly to hit the fish in the back, head to hit it toward tail. This all depends on how deep the fish is. When I go out on my boat, I take my fish arrow, I have different color tape placed at certain depth and I see what the depth of clarity is, then I know if a i can see a fish a foot deep I should aim a minimal of 4" lower than normal. If you can only see 6" or less, don't worry, if you aim at the fish should be good to go. Gar, if a gar is swimming straight for you it is a hard shot, just because the enamel scales are so tough. but likely he will be on the surface, so aim where the mouth first comes out and bam should hit in head.