SUUNTO D9 User Manual
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on to adjust the dive plan in order to maintain oxygen exposure within reasonably sa-
fe limits.
In addition to the physiological effects of enriched air on the body there are operatio-
nal considerations to be addressed when handling altered breathing mixes. Elevated
concentrations of oxygen present a fi re or explosion hazard. Consult with the manu-
facturer of your equipment in regards to its compatibility with nitrox.
1.1.4. FREEDIVING
Freediving, and particularly freediving in combination with scuba diving, may have
risks that have not been researched and are not commonly known.
Any person who engages in any form of breathhold diving is in danger of shallow-wa-
ter blackout (SWB) i.e. the sudden loss of consciousness caused by oxygen starvati-
on.
Any breathhold diving results in some nitrogen build-up in the blood and other fast tis-
sues. Due to the short time spent at depth this build-up is generally not signifi cant.
Therefore, provided the effort involved in freediving has not been severe, there is litt-
le risk in diving after breathhold diving. However, the converse is more unknown and
may increase signifi cantly the risk of DCI. Therefore, FREEDIVING AFTER SCUBA
DIVING IS NOT RECOMMENDED. You should avoid freediving and not exceed fi ve
meters [16 ft] for at least two hours after scuba diving.
Suunto also recommends you to be trained in freediving technique and physiology be-
fore conducting breathhold dives. No dive computer can replace the need for proper