I have been in Boca Chica for 4 out of the last 6 years during the Semana Santa. Technically, motorized boating is not allowed but in practice, I have been able to water ski every day and I have seen divers going out as well.
I've seen dive boats leaving very early in the morning, returning very late in the afternoon, or using alternate launch points outside of the swim areas. I was able to water ski early in the morning or very late in the afternoon, usually an 1/2 hour before sunset.
During Semana Santa, in the swim beach areas, it gets too crowded with swimmers to safely operate a motor boat and Semana Santa is not the only time this happens, it just is one of the few times where the law specifies no motor boats. I have seen plenty of other times where it was too crowded, and legal or not, no responsible operator is going to run a motorized boat through the middle of thousands of swimmers.
So, the real answer is yes, they do outlaw ALL motor boats, but in practice, it is up to discretion. There are alternate launch points such as a marina (there is one next to Boca Chica for example), or one can start of very early and return very late.
I find that in Dominican society, laws are applied as needed rather than without exception and change with the political weather. One day, jet skis everywhere. The next day, no jet skis on any beach. Now jet skis only in very select areas. One day, no motoconcho helmets. The next day, all must have helmets, including passengers. Then only motoconcho drivers. Then the drivers won't be ticketed if they at least are carrying their helmet. Nowadays, few have helmets.
Jim Hinsch JimHinsch@CSI.COM