We go to Aruba quite often, so I thought I would toss in a few ideas. If you want to snorkel, go to Boca Catalina up at the north end of the island. That is where most of the snorkel trips take you, but you can access the good spots from shore, There are three beaches in that area and there is a large area of sea grass which the turtles love. We were there in March and saw lots of turtles. There are not many Palapas and no guys renting umbrellas there. There are also no washrooms (On Shore) and no bars.
Arashi beach up farther is a nice beach with umbrellas and chairs to rent and it now has a bar and washroom.
Closer to your port, Eagle Beach is constantly ranked as one of the beat in the world. There are several resorts there and they are very protective of their chairs, but the beach is public. They have a bar there, and there are washrooms at La Cabana.
To access these beaches you can get a bus at the central bus station across the road from the cruise port. A number 1 bus heads to the High Rise hotels (bus stop at the Amsterdam Manor for Eagle Beach, Holiday Inn area for Palm Beach) and some of them go up to Arashi. Just check with the driver. The bus up to Arashi runs every half hour. The bus fare is $3 US each way.
The beaches are more crowded than when we first started going to Arubi 13 years ago, but then what vacation spot isn't?