• Plan around tide times and slack water where appropriate.
• Check marine forecasts, not just inland weather.
• Carry a DSMB and know how to deploy it before your trip.
• Use appropriate exposure protection for water that can sit below 15°C outside peak summer.
• Treat surge and rocky entries as reasons to abort early, not "push through".
• Dive with a local operator or experienced buddy when visiting a new region.

In an emergency, call 999 or 112. If you are at the coast or at sea, ask for the Coastguard. For suspected decompression illness, administer oxygen if trained and available, keep the diver warm, and arrange urgent medical assessment. The UK has hyperbaric facilities, but access is coordinated through emergency services. Carry diving insurance and keep your insurer's emergency number accessible offline.

The UK has an extensive Marine Protected Area network (including SACs and SPAs with marine components, plus other designations) and site-specific byelaws in some regions. Divers should avoid disturbing wildlife, never remove historical objects, and minimize contact with the seabed, especially in kelp and reef habitats. Use existing moorings where provided, avoid anchoring on sensitive ground, and consider citizen-science programs that support monitoring.