Half-day island tour with snorkeling

[poputchik]

Hello, can anybody recommend a good tour around the island?

We will have a full day (8 am - 10 pm) and would like to leave some time in the afternoon for a self-guided walking tour of Willemstad. What I have in mind, is to spend the first part of the day sightseeing (3-4 hours) followed by 2-3 hours snorkeling on one beach than go back to Willemstad.

I've already checked Irie tours but it looks a little bit hectic with only 1-1.5 hours stays on two beaches. We'd rather spent more time on just one beach.

Any suggestions will be very much appreciated!