Well...I don't know about "allowed" (it's Roatan...are there rules or merely suggestions) but our DM's always had pole spears with them. Once they saw that you had decent dive skills, if you saw a lionfish and got their attention, they would come over and hand you the spear. You would stick the fish and they would stab it with another spear and they would swim over to the next hunter.Are you allowed to hunt them in Roatan as a tourist?
I left Moby friggin lionfish there for you. Biggest LF I have ever seen, and I missed. Fast little boogers when they need to be. He's big for a reason....good luck. You can't miss him, he lives on Rockstar, is at least 5 feet long, glowing green eyes, and tentacles instead of spike fins. I'm pretty sure I heard 80's gangster rap playing once I got close and smelled a blunt. He's sneaky too, he will swim above you and breathe off your Octo sucking your air down to 400 psi. If your quiet, you can hear him still laughing at my miss from 6 inches away..... the horror..... watch your 6.
Next time Moby....next time.
Our dive op did an Island day and cooked the LF on the grill after most of the others tourists had left. I'm sure the location had something to do with it...but it was amazing.
Good luck, safe travels.
Jay