List the ports on the Caribbean cruise so people can comment on them - at some ports you may as well do something else. Also it somewhat depends when/where the ship docks.
For example Grand Cayman at 7AM opens up a lot more options than Grand Cayman at 10am. Since you're tendered on/off, you can't get to the better dive boats if it's later and the diving in town, while easy (two sites are walking distance) and good, isn't the best anymore due to the volume of previous cruise divers. At times I saw 2-3 ships in the harbor, not sure what that does to the transfer times. Someone mentioned that the 3rd ship can hurt the viz as it stays in position on thrusters. Eden Rock, one of the sites in town is literally in front of where they moor.
There are diveops that cater to the cruise traffic (Foster's) but they have much larger boats. Any of 1/2 dozen diveops often mentioned in the Cayman forum limit divers to 6-8 per trip, it's better than 18-24 with Fosters.
I've read that one cruise line moors off Lahaina on Maui now, but the main cruise port is east in Kahului, probably 30-45 mins. each way to the diveboats/shoredives in West Maui or south around Kihei. There's little to no diving near Kahului - there might be one diveop IIRC.
To beat the tradewinds, the Kihei boats go out really early, most around 6-7am so I doubt you could get over there in time unless it's a next morning stay over. A couple of the diveops in West Maui cater to the cruise schedule (Lahaina and Maui Dive shop afaik) with later departures and single tank afternoon dives. Due to the trades, the afternoon boats often dive just off Maui.
We saw some of the largest schools of fish ever offshore of Maui. Hundreds of butterflys, moorish idols etc. - literally more than you can count. But it was mostly off the backside of Lanai than Maui itself - about an hour ride offshore.
Sites like Shark Condos (130' off Molokini) or the St. Anthony wreck just off Maui (60' - dozens of turtles actually
live on the boat) are regularly good. Multiple dive/snorkel boats moor inside Molokini crater daily so the fish are used to a handout - it's not sanctioned but it happens. Talk about fishlife..lol. It's shallow, clear diving - a long swim to break 60' in some areas. I've twice seen reef sharks resting on the sand and once a frogfish hunting in the staghorn.
For turtles Kauai is almost a given. Cruse ships moor at Nawiliwili near Lihue. A few miles south of there is the Poipu area, good for both shorediving and local boat diving. Sheraton Caverns is a boat dive there teeming with huge turtles. There are only a few diveops (SeaSports, Fathom Five ??) in that area so check scheduling. It's riddled with sunken lava tubes and they sleep under the ledges. I've seen everything from 4-5' (loggerhead?) turtles to smaller green turtles that circled around us the entire dive. Didn't exceed 60' IIRC.
I also snorkeled off Poipu Beach, dozens of butterflys and tangs just off the breakwater. If you have kids, there's a flat calm beach area where they can see fish in 3' of water.
Since Hawaii is volcanic substrate, in some areas it's not the beautiful, colorful coral on coral like you might've seen off Nassau. Otoh, in some areas the staghorn is so dense that you can't see the bottom.
The vis is outstanding, probably twice that of Roatan. Once it must've exceeded 200' horizontally - on the surface I could look down and read lettering on people's BC's 80-90' below.
I've done a couple dives off the North Wall on Grand Cayman that matched that also. They warn you to watch your depth as the water is so clear you have no particles to reference as you're dropping. Way down the wall you often see big pelagics feeding. Not sure if it's a doable location from a cruise ship, probably would be if you have all day.
Starting to get the feeling that the reason everyone on here loves it so much is because the ease and volume of diving it affords and not necessarily the quality. Can anybody comment on that?
That's certainly a fair assessment. We did a cheap(er) week on Roatan and had some great dive experiences (sharks, dolphins - paid dives) turtles, grouper, but I'd guess the viz all week in Roatan was about 60-70' everywhere we dove. But at $25-35/dive you get more than you pay for.
We did the AKR dolphin dive (60' dive) the highlight was interacting with them, the lowlight was waiting about 20mins. for them to show up on a vast sandy plain - one poor crab spotted while waiting must've thought his world was ending - we have 4 photogs in our group...lol
A week of diving on Roatan was hit or miss. We mostly dove the north (West End area) and saw turtles on average once per day in 3-4 dives. At some sites there were more fish than you can count, at others comments were made by several in my group back on the boat about how few fish/animals were seen. One site was almost barren, the DM commented that it had been epic the week earlier. Typically north side diving goes deeper down the wall first followed by a shallower second dive. The south side is often shallow for the whole dive.
Anthony's Key does cruise dives or you can do a day at Cocoview. Coconut Tree Divers in the west end is another option, they do two afternoon dives that should allow time to get back to the ship - maybe not the 2nd dive depending on your sail time. There's shopping/food in the West End also for the post-dive - and most of the nightlife. At AKR or CCV, you do everything there.
No experience with Kona - I've been there but not dove, but the two epic dives, the Mantas and the Black Water dive are done at night. So a stay there would seem necessary. Volcanoes Natl' Monument is worth the ride also.
hth,
There are lots of shallow dives, wrecks, deep walls, swim-throughs, too. The reefs are VERY colorful and lush. We have been diving quite a while and we think the reefs there in Roatan are the healthiest we have seen in the Caribbean!!!!
