The problem is you have a very low head situation if you want to routinely be able to harness electricity from waves or tide. With waves, you may be able to do some sort of splash-over mechanism but I can only envision getting a couple gallons per minute and with a 3 to 5 foot drop we're talking a maximum of MAYBE 3 watts.
I'll even work through a best-case scenario:
Even if you routinely get huge waves - say 15 feet - and you manage a trough style intake that can grab 100 gallons of water from each and every wave and each wave is 4 seconds apart...
Your flow rate would be around 1500 gallons per minute and you'd have a drop of about 7-10 feet (keep in mind the water flows back to equilibrium and not to the wave-minimum. That setup would produce a respectable 1500 watts maximum (assuming 10 feet) but then you have to look at how realistic that would be.
If you can only get 3 feet of drop, your power cuts all the way down to 450 watts. If you can only pull in 50 gallons, it gets cut in half again.
Plus you have to deal with the wear and tear that saltwater will do to your components.
Because you have such a reliable and constant wind source on the coast, it will probably be better to stick with that.
I'm not saying that it isn't possible, and there actually is a monstrous amount of power in a 100 foot section of a 3 foot ocean wave, it's just very difficult to reliably harness.