Hiya
Unfortunately, using a reelgun would DEFINITELY put you at a dis-advantage. When diving inside the kelp beds, you're fine with a reelgun, as boaters will very rarely drive through the kelp beds, becuase of the fear of the kelp strands tangling with the props.
In open water, its a NIGHTMARE with a reelgun. We use reelguns exclusively, when hunting for yellowtail in the open water, which normally has very swift current. The boat stays with-in 10m's of us, YET, we still have close call!! Most boaters don't even know what a alpha flag (dive flag) is!!! Some boaters DO know, but still just don't care. Scariest of all, i've even had a fellow spearo drive his boat OVER me whilst i was on the bottom in 5m of water, WITH a float, in dead calm water!! Needless to say, we had words, and are no longer on talking terms. I've even had guys try and pick up my boogie board whilst tuna hunting!!
One of my scarriest moments was coming up from the bottom, after shooting a yellowtail, only to see 4 rapala's (fishing lure's) come swimming past my head!!
For those guys who hasn't encountered a boat yet, its the worst thing imaginable. You can HEAR a boat, but you're absolutely CLUELESS as to from which direction its coming and how close or how far it is from you. NERVE-WRECKING, when you HAVE to surface!!!
Regards
and stay SAFE!!
miles