How to use a buoy float?

Well (In My Opinion)all depends on your diving situation: In general the float line will be attached to the buoy from one side and from the other side it will be connected to your gun (There should be a place to connect the float line on the gun at the back of the gun behind the handle) once you shoot the fish just leave the gun and go up fight the fish from top(This is right except for the fish which will pull your line to the rocks like groupers keep in mind safety and the air in your lungs). 1- If you have calm place with no single current you can just make it 1 or 2 meters longer than the depth your diving. 2- If you have current and you are drifting then depends on the current you will have to give more distance for your float line (because there will be big angle). This is a simple scenario on what you may need, another option would be using a reel depends on your hunt if it is big fish (8 kgs and more using float line is better) if you hunting smaller size fish like max 5 kgs go for reel setup. To get a better answer you might have to explain more on how do you hunt is it from shore? Size of your fish? The current situation? the time you spend in water etc... All best