Dive Computer Terminology

Glossary of technical terms and common acronyms used for diving instrumentation

Acti (wet or button)Activates the computer when you get in contact with water or push the button to start the dive
AlgorithmThe Bühlmann decompression algorithm is a mathematical model (algorithm) of the way in which inert gases enter and leave the human body as ambient pressure changes
ALT adjustableAltitude adjustment for accurate calculation when diving at altitude
Ascent rate indicatorShows you the speed of the ascent of your dive
Audible alarmAcoustic signal for any pre-set parameters which are related to the safety of the diver
BacklightIllumination of the screen underwater
Battery power indicatorShows the current battery level
Bluetooth SmartBluetooth Smart is a low energy wireless personal area network technology, that allows transmission between a dive computer and a mobile device
BookmarkUsed to mark important points during the dive, which can be seen in the DiverLog program
Bourdon tubeA mechanical device that measure pressure
Conservative factor adjustmentWhen the Conservative Factor is set on, the no-decompression limit times are reduced to values equivalent to those that would be available at the next higher 3000 foot (915 meter) altitude
Declination adjustmentAllows you to adjust your compass for ideal accuracy
Deep stopDeep stop is an extra voluntary safety stop at depth prior to the safety stop, which may be set by the diver
Depth alarmWill sound alarm once maximum depth, set by diver, is reached
DownloadDownload updates or settings from DiverLog
Download cableIs the connection to your PC / Mac to upload or download your data
DTR alarmDive Time Remaining alarm
EDT alarmElapsed Dive Time alarm
Free diveDiving without dive cylinder to calculate and track Nitrogen Tissue Loading, allowing you to switch between SCUBA dives and Free Dives on the same dive day
FO2Fraction of oxygen settings, FO2 is the fraction of oxygen in the mixture. For example, if a gas contains 36% oxygen (FO2 = 0.36)
Fresh / salt water selectAbility to select water type, for accuracy of the algorithm’s calculation
Gas integrationContact with your first stage / tank which shows you how much gas you still have in your cylinder
Gas time remainingCalculation of timing remaining based on current depth and gas consumption rate
Gauge modeDivers using advanced breathing gases or diving beyond the limits of the dive computer may utilize the computer as an advanced digital depth gauge and bottom timer with detailed PC Interface
History modeGives you a quick overview of important information from prior dives
Hoseless gas integrationEliminates the need of a traditional hose to provide your pressure information
LCD displayA liquid crystal display (LCD) is a thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs)
LogbookA logbook is used to record the details of your dives
Max depthDeepest point during the dive
Max PO2 alarmAlarm sounds once max PO2 level is reached
Mounting optionA different way of attaching the computer
Nitrox modeSpecifically set to calculate based on your FO2
OLED displayOrganic Light Emitting Diode display is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current, resulting in a crisp,easy-to-read display
Plan modeAllows you to plan and preview your dive in advance
PO2Partial pressure of oxygen. PO2 is a critical component of calculating your maximum oxygen saturation
Run timerSafety stops are considered mandatory by the majority of scuba training organizations for dives deeper than 100 feet or those approaching a no-decompression limit. While not strictly necessary, most dive agencies promote as safe diving practice
Set audible on/offAbility to turn the acoustic alarm on/off
Set deep stop on/offDeep stop is an extra voluntary safety stop in depth next to the mandatory stop in shallow water
Shortcut screenWith a single press of the button, you will see all the main dive information for your logbook
TLBG alarmTissue Loading Bar Graph alarm will sound when maximum rate, set by diver, is reached