We were only ship as well, apprx 3200 pax. I think they can only accommodate 1 per day. We arrived in port 8a, took our time and taxi to resort, $15, about 12-14 minute ride. Arrived 944a, two adults, no problem. Though sign was already posted that they were sold out of kid's passes for the day. I think they consider and count the kids staying on property aa well and limit the total #. Next visit, we would plan to arrive sooner if possible, their office opens 8a local time.
We did not snorkel though several were out doing so. I believe you'll need your own equipment but can contact office prior, they were very responsive leading up to our visit. They do have an onsight dive shop there but I know nothing about it.
The resort is not fancy but it is nice, quiet, relaxing and has all that we needed. $25 pass gets you in and includes $10 bar/restaurant credit..which was one drink each and tasty at that. Hope this helps, enjoy!