Unplanned Decompression (Accidental NDL Overstay)
Purpose
This SOP defines how Sea Saba manages unplanned decompression events during recreational dives. Unplanned decompression is not desired and should be avoided whenever possible. When it does occur, it must be managed conservatively, transparently, and without shortcutting required stops.
Scope
This SOP applies to all Dive Guides, Captains, and Operations Staff involved in guided recreational dives.
Procedure
Policy Statement
Sea Saba operates all recreational dives as no-decompression dives. Unplanned decompression may occur due to diver error, inattention, or unfamiliarity with dive computers. When it does occur, it must be managed conservatively, transparently, and without shortcutting required stops.
Danger
Any decompression obligation must be cleared before exiting the water.
Prevention
Dive Briefing Requirements
Every dive briefing must include:
- Clear explanation of No-Decompression Limits (NDL)
- How to locate NDL on common dive computers
- Reminder to monitor:
- Depth
- Time
- NDL countdown
- Emphasis that entering decompression is not acceptable planning
Nitrox Encouragement
Nitrox is strongly encouraged on all dives. Guides should explain that Nitrox:
- Extends NDL
- Adds safety margin
- Reduces likelihood of accidental decompression
Immediate Actions When a Diver Enters Decompression
In-Water Response
If a diver enters decompression:
- The guide must immediately assume responsibility for that diver
- The diver must remain underwater until all required decompression is cleared
- All required decompression stops must be completed
- Do not shorten or violate stops
- Follow the diver's computer exactly
Communication With the Boat
As soon as possible, and without leaving the diver unattended, the guide surfaces briefly to inform the boat of:
- Diver in decompression
- Estimated decompression time
- Depth of stops
- Whether additional support is required (e.g., hang line, extra tank)
Warning
This communication must happen as quickly as possible to minimize time the diver is unattended and delay in support deployment.
Supervision Requirements
The diver in decompression must be accompanied by the guide for the entire process. The guide must:
- Monitor the diver
- Monitor the diver's computer
- Ensure all stops are fully completed
Danger
The diver must not ascend to the surface until the computer is fully cleared.
Completion of Decompression
Clearance Confirmation
- Confirm the dive computer shows no remaining decompression obligation
- Only after clearance may the diver exit the water
Additional Safety Stop
After clearing required decompression, an additional 3-minute safety stop is highly encouraged, conditions permitting.
Post-Dive Actions
Documentation
Any unplanned decompression must be recorded on the dive manifest. Notes should include:
- Diver name
- Dive number
- Approximate decompression time
- Any support actions taken
Diver Communication
The diver must be clearly informed that:
- Entering decompression is not acceptable
- They are expected to actively monitor NDL
- This should not happen again
Tone should be calm, professional, direct, and safety-focused.
Enforcement
Uncleared Decompression
Danger
If a diver exits the water without clearing decompression, a 24-hour dive ban will be enforced.
Repeated Incidents
If a diver enters unplanned decompression again, further restrictions may be enforced, including:
- Mandatory Nitrox
- Shallower depth limits
- Increased guide supervision
- Removal from advanced dives
Guiding Principle
Unplanned decompression:
- Is not a planned activity
- Is not acceptable as routine behavior
- Must be treated seriously but professionally
The goal is to maintain diver safety, protect guides and captains, preserve operational integrity, and encourage safer dive practices.
Bottom line: Encourage Nitrox. Monitor NDL. Clear all decompression. Document everything.
Accountability
Dive Guides are responsible for briefing NDL awareness, managing in-water decompression events, and communicating with the boat. Captains are responsible for coordinating surface support during decompression events. Operations Staff are responsible for enforcing dive bans and restrictions following incidents. All staff share responsibility for accurate documentation.