I know of one place in Cuba, wahoo and billfish 100 yards from shore. I put a securing shot in a sailfish there after it was hooked from shore. I don't think such a place exists in continental US. Unless something like a cobia run happens with other species which I'm not aware of.
I can see George's float is fine drag wise. I made something like it myself years ago for inshore use, it also had a flag and ballast http://spearfishing.world/floa…ds/27-diy-float-flag.html

Here's a thread on the lifeguard can float http://spearfishing.world/floa…ard-rescue-can-float.html. With 4lb density foam which has some crush resistance the float was quite heavy to carry with the rest of the gear, but in the water had very little drag.

A float system choice is a balance between lift, crush resistance, drag for diver, drag for fish (which are kinda' the same consideration) convenience of transporting, availability of materials if making your own, and price. You can go with huge lift capacity and get away with the cheap lobster floats (which have very little crush resistance) problem is if the fish is powerful and goes deep unable to take the floats down, the shaft will tear out. If the floats provide just enough lift that they're hard to take down but eventually do get taken down before the shaft tears out, they need to be crush resistant.
If I was going to rig for bluewater I'd choose a compact float system with great lift and negligible crush resistance, and use a bungee for at least part of the float line to apply steady pressure on the fish and prevent shaft tear out.



