Safety · Destination Guide
Descend through cold, clear history onto the warships of Scapa Flow
Scapa Flow combines serious cold-water wreck risk with unusually strong local support. The central anchorage can be sheltered, but depth, darkness, silt, entanglement, decompression, changing weather and active harbour traffic demand a conservative team. Use a qualified local skipper, dive within current experience, and regard site changes as a safety decision rather than a lost booking. Stromness has a fully operational hyperbaric unit with 24/7 NHS-funded cover, but that proximity should never justify aggressive profiles. The protected wreckscape is also a cultural responsibility: leave every artifact and fitting exactly where it lies.
At sea, suspected decompression illness or another serious incident should be reported immediately to the skipper or dive supervisor, who should contact the Coastguard. Use VHF DSC or Channel 16 for a marine emergency. Ashore, call 999 or 112 for emergencies and follow the Scottish diving-medicine pathway.
The Orkney Hyperbaric Trust operates the Bobby Forbes Unit in Stromness and states that it provides NHS-funded hyperbaric cover 24/7 for recreational and commercial diving. NHS National Services Scotland lists Stromness as a Category 2 chamber alongside the Category 1 service at Aberdeen Royal Infirmary. At sea, the local unit advises routing a suspected decompression illness through the skipper or supervisor and Coastguard so assessment, transport and chamber mobilization begin together. For symptoms that appear ashore after diving, the Orkney Hyperbaric Trust advises calling Balfour Hospital on +44 1856 888000 and asking for the doctor on the diving rota. The Scotland DCI helpline is 0345 408 6008.
Cold water and decompression load
Fleet-wreck routes can be cold, dark and deep enough to create mandatory stops. Use a configuration, gas supply and thermal plan that remain adequate after delays, current changes or a missed feature.
Wreck overheads, silt and entanglement
Torn plating, cables, nets and enclosed spaces can turn an appealing opening into a serious overhead. Enter only with matching training, team procedures, redundant lights and an appropriate line plan.
Burra Sound tide
Blockships in Burra Sound sit in a strong tidal channel. Slack water is essential, and the skipper's timing overrides a diver's preferred schedule or site sequence.
Surface weather and transport disruption
Scapa Flow is sheltered, but Orkney remains exposed to Atlantic wind. Rough transits, site swaps, ferry disruption and cancelled days are real planning risks in every season and increase in winter.
The Scapa Flow Historic Marine Protected Area has protected wartime wrecks and artifacts since 1 November 2025. The seven German fleet wrecks also have Scheduled Monument protection. Divers may look, photograph and appreciate them under the applicable harbour and vessel permissions, but must not touch, tamper with, move, recover or remove material. Do not tie into fragile structure, force an opening, feed wildlife or stage equipment on archaeological features. Report significant new damage or finds to the skipper rather than disturbing the site.
HMS Royal Oak and HMS Vanguard are protected controlled war-grave sites. Recreational diving is prohibited within their controlled areas, and the losses should be discussed and viewed with memorial respect. Follow additional exclusions around Flotta oil infrastructure, pipelines and any site closed by Marine Services. Good buoyancy protects both archaeology and the artificial-reef communities that now cover the wrecks.
Do Not Do This
Avoid entering when cold water and decompression load. Confirm local briefings before committing.
| Contact | Role | Phone | Availability |
|---|---|---|---|
| UK Emergency Services and HM Coastguard | Life-threatening emergency ashore or at sea; ask for the Coastguard for marine incidents | 999 or 112; VHF DSC or Channel 16 at sea | 24/7 |
| Scotland Decompression Illness Helpline | Urgent diving-medicine advice and coordination with Aberdeen Royal Infirmary | 0345 408 6008 | 24/7 |
| Orkney Hyperbaric Trust | Stromness recompression facility; emergency access should follow the Coastguard or diving-medicine pathway | +44 1856 850285 or +44 1856 851668 | 24/7 hyperbaric cover |
| Balfour Hospital | For diving symptoms presenting ashore, ask for the doctor on the diving rota | +44 1856 888000 | 24/7 hospital contact |
| Orkney Islands Council Marine Services | Harbour diving permission, VTS coordination and operating restrictions | +44 1856 873636; VHF Channel 11 for VTS reporting under the permit | Confirm current office and VTS operating arrangements |