Negombo and Marawila

Before Leaving Shore

• Require a current weather/sea assessment, named guide, suited certification and recent experience, buddy plan, actual boat departure, return plan, site depth and maximum planned profile.
• Ask for inspected equipment and cylinders, recognized training credentials, a site-specific briefing and emergency oxygen plus trained responders. Confirm rescue communications, diver-down flag, surface marker and safe entries/exits.
• The SLTDA registration guideline states a limit of 30 m for dives; its Discover Scuba guidance limits trial dives to 12 m. Exclude operator-catalog wrecks advertised deeper than the stated limit. No technical, cave, wreck-penetration or overhead activities are endorsed.
• Bring documents and insurance confirmation. Ensure the operator knows any relevant dive medical screening results, without treating a generic waiver as medical clearance.

In the Water

• Expect fishing nets around some wrecks, occasional currents and variable visibility at offshore reefs. Avoid physical contact with coral, wreck debris or animals. Do not remove heritage items or feed sharks.
• Snorkelers need a separately approved itinerary, guide/lookout and flotation; a recreational dive depth description does not establish a safe snorkel entry.
• Freedivers require dedicated buddy supervision and rescue training. Never practice breath holding alone, hyperventilate or accept a scuba guide as proof of a qualified apnea safety diver.

After the Dive

• Observe appropriate post-dive flying intervals. DAN guidance advises at least 12 hours for a single no-decompression dive and at least 18 hours for repetitive or multiday no-decompression dives; more time is needed for some profiles and individual situations. A non-diving final day is a prudent travel buffer.
• Seek emergency assessment after suspected decompression illness, neurological symptoms or major barotrauma; do not wait for symptoms to resolve or self-direct air travel. Arrange oxygen and emergency transportation through trained professionals.

The priority for dive injuries is trained first response, 100% emergency oxygen when indicated, local ambulance/medical evaluation and coordination for specialist evacuation. An October 1, 2026 Sri Lanka Navy statement confirms a recompression facility at the Navy Diving Unit in Trincomalee, across the country from this west-coast area. No functioning chamber in Negombo or Marawila, definite transfer time, guaranteed civilian admission or 24-hour recompression availability was independently confirmed. Before diving, ask the operator to identify the closest functioning emergency department, doctor, oxygen source, actual medical evacuation route, receiving recompression provider and insurer contact. Call 1990 for an ambulance in a medical emergency and use maritime distress services as appropriate. Mosquito-borne illness remains a general traveler concern; use repellent and local public-health advice, particularly for marsh visits.

Coral reefs and historic remains are sensitive and some wreck structures can be unstable. Maintain buoyancy, do not anchor on live reef where avoidable, do not remove artifacts or shells, and do not touch or chase rays, sharks or other animals. The SLTDA registration guideline explicitly cautions against coral damage, taking cultural artifacts, feeding sharks and unapproved activity in protected areas. Muthurajawela is an environmentally protected wetland, so use approved access and keep noise and litter down. Negombo Lagoon water-quality research is a reason for care around lagoon swimming and runoff, but it must not be presented as a measurement of offshore dive visibility or pollution. Marine-mammal interaction rules are separate from reef diving: avoid unauthorized swimming with, chasing or harassing whales and dolphins. Wildlife encounters cannot be guaranteed.