My favorite Shrip Truck is Giovanni's in Kahuku.
Giovanni's Shrimp Truck The North Shore is nice but winter is big wave season snorkeling at Sharks Cove probably won't be an option. I have done many NCDs (Night Combat Dives) there. I would stick to Hanauma Bay it is like swimming in an aquarium. In the summer months the surf is bigger on the South and West shores, in the winter the big swells come and hit the North and East shores.
Disclaimer: I am not a Combat Diver my buddy and I just referred to our night dives there as such due to the level of difficulty, going out in less than pristine conditions, and the abuse suffered.