Pick operators who are honest about weather, not operators who promise a fixed site list. Carry an SMB on boat dives and treat exposed Atlantic plans with respect, especially around Samana and some east-coast days. For beginners, the southeast is the safest national default. For deeper wrecks, make the site fit your certification and recent experience rather than the other way around. Shore or boat entries can still involve current, chop, ladder climbs, and uneven surfaces, so good fin discipline and exit awareness matter even in warm tropical water.

Tourist zones and large cities have the country's strongest private medical infrastructure, while more remote or weather-exposed areas can add transfer time in serious incidents. Dial 911 for police, ambulance, or fire response. Keep your operator's nearest hospital plan and emergency oxygen procedure clear before departure. Divers should carry dive accident insurance with evacuation support and should confirm the nearest practical recompression pathway with their operator or DAN-style insurer before splashing, especially outside the southeast resort corridors.

The Dominican Republic's protected-area system includes a large national network and a significant recent expansion of marine protection. Cotubanama National Park helps frame the southeast island-and-reef experience, while Samana whale watching is regulated through authorized operators under environmental oversight. Support operators that use moorings, brief clearly on no-touch practices, and avoid wildlife harassment. Do not stand on coral, collect shells or reef life, or assume drone or wildlife access is unrestricted inside protected landscapes. Reef-safe sunscreen, good buoyancy, and restraint around feeding or chasing animals are simple traveler actions that matter.