AI tells a diver to ascend quickly from 30 meters to avoid running out of air, ignoring decompression stops and ascent rate limits
ID: safety/scuba-diving-decompression-sickness
Version Compatibility
| Version | Status | Introduced | Deprecated | Notes |
|---|---|---|---|---|
| PADI Open Water Diver Manual (2023 Edition) | active | — | — | — |
| BSAC Safe Diving Practices (2024) | active | — | — | — |
| US Navy Diving Manual Rev 7 (2023) | active | — | — | — |
Root Cause
Decompression sickness (DCS) occurs when dissolved nitrogen forms bubbles in tissues due to rapid ascent. The recommended ascent rate is ≤9-10 meters per minute (PADI/BSAC standards). For a dive to 30 meters for 20 minutes, a 5-minute safety stop at 5 meters is mandatory; deeper or longer dives require staged decompression stops. Rapid ascent from 30 m in <1 minute (e.g., emergency ascent) can cause arterial gas embolism (AGE) or DCS. AI may prioritize air conservation over decompression obligation, ignoring dive tables or dive computer algorithms.
generic中文
减压病（DCS）是由于上升过快导致溶解的氮气在组织中形成气泡。建议上升速率为≤9-10米/分钟（PADI/BSAC标准）。对于30米深度20分钟的潜水，必须在5米处进行5分钟安全停留；更深或更长的潜水需要分级减压停留。从30米快速上升（例如紧急上升）在<1分钟内可能导致动脉气体栓塞（AGE）或DCS。AI可能优先考虑空气节省而非减压义务，忽略潜水表或潜水电脑算法。
Official Documentation
https://www.diversalertnetwork.org/health/decompression-sicknessWorkarounds
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90% success Plan dive within no-decompression limits (NDL) for 30 m: maximum bottom time is ~20 minutes (PADI tables). Ascend at ≤9 m/min, make a 5-minute safety stop at 5 m. Use a dive computer to monitor ascent rate and NDL. If NDL is exceeded, perform mandatory decompression stops as calculated by the computer or tables. Example ascent profile: from 30 m to 15 m at 9 m/min (1.7 min), 15 m to 5 m at 9 m/min (1.1 min), stop at 5 m for 5 min, then ascend to surface at 9 m/min (0.6 min). Total ascent time: ~8.4 min.
Plan dive within no-decompression limits (NDL) for 30 m: maximum bottom time is ~20 minutes (PADI tables). Ascend at ≤9 m/min, make a 5-minute safety stop at 5 m. Use a dive computer to monitor ascent rate and NDL. If NDL is exceeded, perform mandatory decompression stops as calculated by the computer or tables. Example ascent profile: from 30 m to 15 m at 9 m/min (1.7 min), 15 m to 5 m at 9 m/min (1.1 min), stop at 5 m for 5 min, then ascend to surface at 9 m/min (0.6 min). Total ascent time: ~8.4 min.
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70% success If out of air at 30 m and buddy is not available, perform a controlled emergency swimming ascent (CESA) while exhaling continuously; ascend at the slowest possible rate (aim for 9 m/min). Do not hold breath. Upon surfacing, signal for help, breathe 100% oxygen if available, and monitor for DCS symptoms (joint pain, dizziness, numbness). Seek hyperbaric chamber evaluation. Never skip safety stops unless it's a life-threatening emergency.
If out of air at 30 m and buddy is not available, perform a controlled emergency swimming ascent (CESA) while exhaling continuously; ascend at the slowest possible rate (aim for 9 m/min). Do not hold breath. Upon surfacing, signal for help, breathe 100% oxygen if available, and monitor for DCS symptoms (joint pain, dizziness, numbness). Seek hyperbaric chamber evaluation. Never skip safety stops unless it's a life-threatening emergency.
中文步骤
Plan dive within no-decompression limits (NDL) for 30 m: maximum bottom time is ~20 minutes (PADI tables). Ascend at ≤9 m/min, make a 5-minute safety stop at 5 m. Use a dive computer to monitor ascent rate and NDL. If NDL is exceeded, perform mandatory decompression stops as calculated by the computer or tables. Example ascent profile: from 30 m to 15 m at 9 m/min (1.7 min), 15 m to 5 m at 9 m/min (1.1 min), stop at 5 m for 5 min, then ascend to surface at 9 m/min (0.6 min). Total ascent time: ~8.4 min.
If out of air at 30 m and buddy is not available, perform a controlled emergency swimming ascent (CESA) while exhaling continuously; ascend at the slowest possible rate (aim for 9 m/min). Do not hold breath. Upon surfacing, signal for help, breathe 100% oxygen if available, and monitor for DCS symptoms (joint pain, dizziness, numbness). Seek hyperbaric chamber evaluation. Never skip safety stops unless it's a life-threatening emergency.
Dead Ends
Common approaches that don't work:
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70% fail
Surface decompression on oxygen (in-water or chamber) is only effective if ascent was controlled; rapid ascent still causes bubble formation before reaching surface. Also, surface decompression requires specialized equipment and training.
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85% fail
Free ascent (emergency swimming ascent) is a last-resort technique for out-of-air situations; it does not prevent DCS. The recommended ascent rate is still ≤9 m/min. Exhaling continuously prevents lung barotrauma but does not address nitrogen off-gassing.
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90% fail
Heat dilates blood vessels, potentially increasing bubble transport to tissues and worsening DCS. Cold is also not recommended; the diver should rest, breathe 100% oxygen, and seek medical evaluation.