I tried and tried to get a shot like this last summer. I took a beating with the waves, had salt water up my nose, sand in my suit, and just plain tossed around....and I still didn't get anything quite like this. Terrific image. A HUGE 10 from me!
Amazing that you captured a good shot of being inside the curl of a wave! It is a good shot but has the potential of being an exceptional shot had the crest of the wave been in sharper detail. Undoubtly getting a shot in side a wave is difficult so tis understood that to get it in full sharp detail is a challenge, but it is not unachievable. I see that the sharper focus is on the mountain backdrop and the portion of the wave that is closest to the backdrop. Perhaps a higher aperture would get you a better DOF of foreground and background but that would also possibly mean bumping up the ISO a bit more so that the photo is not dark. Lastly show off your photo! I think the large black border just detracts from the composition - it drowns it in a heavy black border that makes it smaller. A thin black border would better complement the shot.