Disney age restriction: looking for cruise, snorkle, beach

We have 2 families and grandparents (total 11) sailing Disney Wonder with St Thomas as stop. We really want to do the all ("most of") day sail/motor-boat which visits various bays of St Thomas, with stops to snorkle and beach time.

Unfortunately, the youngest member of our group is less than 2 months shy of 5 years old, the minimum age for the Disney excursion. The almost 5 year old is a good swimmer, loves the outdoors, and is well behaved.

So we're hoping to do the equivalent "excursion" with an independent. One concern I have is that this is a tender boat port, and that makes it unpredictable when we get off the ship in the morning.

I'm asking for:

- suggestions for tours/operators which can provide this kind of excursion and still get us back to the boat in time.

- suggested places for the tour to visit

- logistical experiences of going from Disney cruise via tender boat to the island

- what location of St Thomas does Disney tender boats drop off?

- how do we get to the tour operator from the drop off?

We are first timers to the island and normally do the beach, water, and eating thing when we go to Hawaii, our more frequent island destination. We all are very comfortable in the ocean.

Disney does not typically tender in at St Thomas. Are all 11 going to be going on this excursion? If you want to do your own excursion, you will probably need to taxi to one of the marinas.

Be cautious letting a five year old snorkel, unless she is used to swimming in the ocean. It is not at all like a pool, and snorkel excursions take place in 15 - 50 feet deep water, often with a lot of chop.

There is a reason Disney has age restrictions.

St Thomas is one of the easiest places to get around on your own. You could just grab a taxi when you get off the ship and go to one of the beaches.....Coki or Meghans Bay are popular with cruisers.