Last year was my first trip to Kauai, and I’ll share what I learned. I’ve read many recommendations to only attempt Sheraton Caverns from a boat, and after diving there I can see why. It’s quite a ways off shore and the water was rough the day we went. A current can ruin your vacation. I dove that day with Seasport Divers and dove Turtle Bluff’s too. Both cool sites. TB was great for white tip reef sharks and turtles the size of Volkswagon Bugs. Sheraton was cool for the caverns and coral garden on top. There are a bunch of dive shops in the Poipu area where all the boats go out of (South shore), and I’m sure they are very comparable. I picked Seasport for two reasons, easy to find with a yellow submarine in front, and they are best known for their Niihau trips. Sounds like it’s not an option for you in Nov. Too Bad. I would still ask just in case the weather was good. And if you go, use a sea sick patch for sure. Best dives to be had from Kauai hands down.
As for shore dives, I’m sure there are more than these, but the two best known are Tunnels on the North end of the island and Koloa Landing near Poipu on the South coast. For a Northern dive at Tunnels, Seasport divers has a convenient shop in Kapaa, half way there for renting tanks. So if you are staying in the North this would be your dive shop of choice. Tunnels was cool. Parking is best during the week and fills up early, generally by 10am. From the lot it is a 60 yard hike across grass, and then 100 yards across soft beach sand. When it’s hot out and carrying gear it can be grueling to cross that sand. I went straight out from the nearest beach entry and surface swam to the right to where the reef is. Can’t miss it. There will be tons of snorkelers over the shallow reef. Only you get to go deeper :-) I haven’t dove Koloa Landing yet, but heard you can park right next to the entry spot. I plan to dive there in April for my next visit. Have fun! And don’t miss breakfast at the Kuntry Kitchen in Kapaa. The chocolate chip pancakes and coconut syrup is to die for....