Don't forget a Geiger counter to check radiation on flotsam that may have come by way of Fukushima.

"Sea Vegetables" by Evelyn McConnaughey is a pretty good book on edible seaweeds.
http://www.amazon.com/Vegetables-Harvest...=sea+vegetables

-Blast

Do you really need any? I saw plenty of detailed online reports on abalone foraging and general dive hunting, which includes the strategy and tactics you can follow to succeed. What I would highly recommend instead is to have a dive buddy, even if only the one watching you from ashore.

For the diving gear it would be nice to add a float on a rope and some weights to make diving in wetsuit easier.

By the way, to the end of the past summer the water here became so warm that it was possible to swim without a wetsuit. Not that I'm suggesting doing that but that's definitely a nice trend for any diver here.

Thanks.