Suunto D4i User Guide
Surface and no-fly time
Once back at the surface, Suunto D4i continues to provide post-dive safety information and alarms. If, after your dive, you need to wait until flying, the no-fly symbol displays in all modes.
To access further information about your surface and no-fly times, enter dive mode.
Suunto D4i shows the time since you surfaced in the Surf t. field. The airplane symbol indicates that you should not fly. The countdown until you will be safe to fly is shown in the No Fly field.
No-fly time is always at least 12 hours and equals desaturation time when it is more than 12 hours. For desaturation times shorter than 70 minutes, the no-fly time is not displayed.
If decompression is omitted during a dive so that Suunto D4i enters error state (see Error state (algorithm lock)), the no-fly time is always 48 hours.
YOU ARE ADVISED TO AVOID FLYING ANY TIME THE COMPUTER COUNTS DOWN THE NO-FLY TIME. ALWAYS ACTIVATE THE COMPUTER TO CHECK THE REMAINING NO-FLY TIME PRIOR TO FLYING! Flying or traveling to a higher altitude within the no-fly time can greatly increase the risk of DCS. Review the recommendations given by Divers Alert Network (DAN). There can never be a flying-after-diving rule that is guaranteed to completely prevent decompression sickness!
The Divers Alert Network (DAN) recommends the following on no-fly times:
- A minimum surface interval of 12 hours would be required in order to be reasonably assured a diver will remain symptom free upon ascent to altitude in a commercial jetliner (altitude up to 2,400 m (8,000 ft)).
- Divers who plan to make daily, multiple dives for several days, or make dives that require decompression stops, should take special precautions and wait for an extended interval beyond 12 hours before a flight. Further, the Undersea and Hyperbaric Medical Society (UHMS) suggests divers using standard air cylinders and exhibiting no symptoms of decompression sickness wait 24 hours after their last dive to fly in an aircraft with cabin pressure up to 2,400 m (8,000 ft). The only two exceptions to this recommendation are:
- If a diver has less than two (2) hours total accumulated dive time in the last 48 hours, a 12 hour surface interval before flying is recommended.
- Following any dive that required a decompression stop, flying should be delayed for at least 24 hours, and if possible, for 48 hours.
Suunto recommends that flying is avoided until all the DAN and UHMS guidelines, as well as the dive computer’s no-fly conditions, are satisfied.