Time to surface (TTS)[minutes]: Total duration of ascent from critical point of dive in case of emergency. Problem solving duration minutes are added to ascent duration to be able respond to situation at depth as recommended during scuba trainings.No decompression time[minutes]: The longes time diver can stay at required depth where direct ascent to the surface is considered to be safe. There may be small deco, which disappears during the ascent.Maximum bottom time[minutes]: The longest time diver can stay at required depth considering provided gases. Even, it may lead to decompression dive.Rock bottom attime: The moment at which the emergency ascent is calculated used to calculate the rock bottom. It is the last moment at highest depth.
Emergency ascent may differ from calculated ascent, because it is calculated at different time during the dive.
There are usually two types of oxygen toxicity considered:
- Central Nervous System toxicity (CNS): manifests as symptoms such as visual changes (especially tunnel vision), ringing in the ears (tinnitus), nausea, twitching (especially of the face), behavioral changes (irritability, anxiety, confusion), and dizziness. This unit is measured in percents from exposure time limits.
- Pulmonary oxygen toxicity (OTU): Pulmonary toxicity symptoms result from an inflammation that starts in the airways leading to the lungs and then spreads into the lungs (tracheobronchial tree). The symptoms appear in the upper chest region (substernal and carinal regions). This begins as a mild tickle on inhalation and progresses to frequent coughing. If breathing increased partial pressures of oxygen continues, patients experience a mild burning on inhalation along with uncontrollable coughing and occasional shortness of breath (dyspnea).
See also Oxygen toxicity at wiki. For both units there is a NOAA recommendation which our application follows. If any of these units reaches 80 % of its limit a warning is shown.