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Dive profile
A dive profile is a description of a diver's pressure exposure over time. It may be as simple as just a depth and time pair, as in: "sixty for twenty," (a bottom time of 20 minutes at a depth of 60 feet) or as complex as a second by second graphical representation of depth and time recorded by a personal dive computer. Several common types of dive profile are specifically named, and these may be characteristic of the purpose of the dive. For example, a working dive at a limited location will often follow a constant depth (square) profile, and a recreational dive is likely to follow a multilevel profile, as the divers start deep and work their way up a reef to get the most out of the available breathing gas. The names are usually descriptive of the graphic appearance.
The intended dive profile is useful as a planning tool as an indication of the risks of decompression sickness and oxygen toxicity for the exposure, to calculate a decompression schedule for the dive, and also for estimating the volume of open-circuit breathing gas needed for a planned dive, as these depend in part upon the depth and duration of the dive. A dive profile diagram is conventionally drawn with elapsed time running from left to right and depth increasing down the page.
Many personal dive computers record the instantaneous depth at small time increments during the dive. This data can sometimes be displayed directly on the dive computer or more often downloaded to a personal computer, tablet, or smartphone and displayed in graphic form as a dive profile.
The profile of a dive is the variation of depth, measured as ambient pressure, over time during that dive. The actual location of the diver at any time is generally not considered, as the dive profile is a tool for dive planning and decompression status calculation. Other data may be added to the depth graph, such as partial pressures of the breathing gas constituents, calculated estimates of accumulated gas concentrations in the theoretical tissue, gas consumption rates and cumulative gas consumption. These additional values are available when the dive computer uses them to estimate decompression status, to provide the diver with a recommend decompression schedule for the exposure of the actual dive.
Some types of dive profile have been named. An analysis of dive profiles logged by dive computers by the Divers Alert Network used categorization rules which were based on the fraction of the dive time spent in four depth zones: descent, bottom, multilevel, and decompression. The descent zone was defined as the part of the dive between the surface and first reaching 85% of the maximum depth. The bottom zone is the part of the dive deeper than 85% of maximum depth. The multilevel zone is ascent from 85% to 25% of maximum depth, and the decompression zone is less than 25% of maximum depth. A square dive profile was defined as having more than 40% of the total dive time in the bottom zone and not more than 30% in the multilevel and decompression zones. A multilevel was defined as having at least 40% of the total dive time in the multilevel zone. All other dives are considered to be intermediate.
A dive computer will usually record the actual dive profile in real time, in a format that can be downloaded and viewed later. Depth (pressure) values are recorded at intervals which are usually 30 seconds or less, along with other measured data at that time.
If the pressure is measured manually by pneumofathometer by the diving supervisor it will also be recorded manually when it changes. The detailed profile does not generally need to be logged as the maximum depth is used with tables unless a multilevel dive profile is required, in which case the time will be logged for each change of depth, and for the start and end of each decompression stop.
Or constant (bottom) depth profile. The diver descends directly to maximum depth, spends most of the dive at maximum depth and then ascends directly at a safe rate, with any required decompression. The sides of the "square" are not truly vertical due to the need for a slow descent to avoid barotrauma and a slow ascent rate to avoid decompression sickness. The term has also been used more loosely, for example DAN's definition of more than 40% of total dive time in the bottom zone which is within 15% of maximum depth.
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Dive profile AI simulator
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Dive profile
A dive profile is a description of a diver's pressure exposure over time. It may be as simple as just a depth and time pair, as in: "sixty for twenty," (a bottom time of 20 minutes at a depth of 60 feet) or as complex as a second by second graphical representation of depth and time recorded by a personal dive computer. Several common types of dive profile are specifically named, and these may be characteristic of the purpose of the dive. For example, a working dive at a limited location will often follow a constant depth (square) profile, and a recreational dive is likely to follow a multilevel profile, as the divers start deep and work their way up a reef to get the most out of the available breathing gas. The names are usually descriptive of the graphic appearance.
The intended dive profile is useful as a planning tool as an indication of the risks of decompression sickness and oxygen toxicity for the exposure, to calculate a decompression schedule for the dive, and also for estimating the volume of open-circuit breathing gas needed for a planned dive, as these depend in part upon the depth and duration of the dive. A dive profile diagram is conventionally drawn with elapsed time running from left to right and depth increasing down the page.
Many personal dive computers record the instantaneous depth at small time increments during the dive. This data can sometimes be displayed directly on the dive computer or more often downloaded to a personal computer, tablet, or smartphone and displayed in graphic form as a dive profile.
The profile of a dive is the variation of depth, measured as ambient pressure, over time during that dive. The actual location of the diver at any time is generally not considered, as the dive profile is a tool for dive planning and decompression status calculation. Other data may be added to the depth graph, such as partial pressures of the breathing gas constituents, calculated estimates of accumulated gas concentrations in the theoretical tissue, gas consumption rates and cumulative gas consumption. These additional values are available when the dive computer uses them to estimate decompression status, to provide the diver with a recommend decompression schedule for the exposure of the actual dive.
Some types of dive profile have been named. An analysis of dive profiles logged by dive computers by the Divers Alert Network used categorization rules which were based on the fraction of the dive time spent in four depth zones: descent, bottom, multilevel, and decompression. The descent zone was defined as the part of the dive between the surface and first reaching 85% of the maximum depth. The bottom zone is the part of the dive deeper than 85% of maximum depth. The multilevel zone is ascent from 85% to 25% of maximum depth, and the decompression zone is less than 25% of maximum depth. A square dive profile was defined as having more than 40% of the total dive time in the bottom zone and not more than 30% in the multilevel and decompression zones. A multilevel was defined as having at least 40% of the total dive time in the multilevel zone. All other dives are considered to be intermediate.
A dive computer will usually record the actual dive profile in real time, in a format that can be downloaded and viewed later. Depth (pressure) values are recorded at intervals which are usually 30 seconds or less, along with other measured data at that time.
If the pressure is measured manually by pneumofathometer by the diving supervisor it will also be recorded manually when it changes. The detailed profile does not generally need to be logged as the maximum depth is used with tables unless a multilevel dive profile is required, in which case the time will be logged for each change of depth, and for the start and end of each decompression stop.
Or constant (bottom) depth profile. The diver descends directly to maximum depth, spends most of the dive at maximum depth and then ascends directly at a safe rate, with any required decompression. The sides of the "square" are not truly vertical due to the need for a slow descent to avoid barotrauma and a slow ascent rate to avoid decompression sickness. The term has also been used more loosely, for example DAN's definition of more than 40% of total dive time in the bottom zone which is within 15% of maximum depth.
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