Boca Catalina, Arashi Beach Manchebo Beach, Eagle Beach
As far as cruises go, we've found that there are usually just a handful of kids when we cruise during the school year. During school breaks and summer, the ships are full of kids, many barely supervised. As far as hotels in Aruba, we've noticed that there are usually just a few, if any, when we've stayed at Manchebo. Ofcourse, that is subject to change. We've stayed there around President's Week several times, and have only seen a few kids.
For Aruba, Renaissance marina tower or the Bucuti.
For a cruise, as hatteras suggested, when the kids are in school. Trans Atlantic cruises are great for this. The length of the cruise combined with timing make them an excellent opportunity for cruising with few children. AND an excellent bargain besides.
On a cruise I would also highly suggest Celebrity Cruise Lines Aqua Class with the Aqua Class dining room dedicated solely to guests who have booked this category. Not many parents wishing to pay extra for Aqua Class fine dining for their kids when they eat off the kids menu every night.