If the hook isn’t coming out with the dehooker, it’s time to grab the bolt cutters.   

These will cut right through a 12/0 mustad J hook…

Or a 20/0 mustad circle hook.

The idea is to get the shark back into the water in less than a minute.  If you keep them out any longer, release becomes harder.  Especially while you are walking a fish out backwords into heavy surf.