how do you deal with snags in the ocean?

First I use 40-65# braid main line with a 30# three foot Berkeley Big Game leader. This allows me to have an inexpensive, abrasion resistant leader which will consistently break under maximal pressure from a kayak and I don't lose any main line or swivel.

Second when I first get hung up, I free spool it to figure out if I am hung on the bottom, hung on kelp or hung on a fish which went down a hole.

You can feel the friction of kelp on spectra and I usually lower it and then reel up real slow. If that doesn't work I use Bill's jackhammer technique.

If I am hung on the bottom or have a fish in a hole, I free spool it and whip the line several times. Then I paddle up drift and whip it a few more times then reel in the slack and crank hard. Then if I am in a Hobie I use the O2B 360 degree cruise under tension around the lure. If this doesn't work, I button down the drag and bust it out from the up drift position. I try to not use expensive stuff like butterfly jigs so losing one is no big deal. If you are sure it is a fish in a hole you can pull to tension and twang the line like a guitar. It is annoying and sometimes they will swim out.