Oceanic Geo 4.0 setup guide
Also covers: Geo 4, Oceanic Geo 4.0, Geo4
Four-button watch-style computer (MODE, SELECT, ADV, LIGHT) with Watch, Norm (Air/Nitrox, 2 gases), Gauge and Free modes, a choice of two algorithms (DSAT or Z+) and Bluetooth. Gas settings go back to Air after 24 hours without a dive. User-replaceable CR2430 battery.
Buttons
| Button | Where | What it does |
|---|---|---|
| MODE | front, upper left | Move back through the menu / decrease a value; hold: switch Watch ↔ dive mode, or exit to Main |
| SELECT | front, upper right | Select / save; silence an alarm; hold: step back |
| ADV. | front, lower left | Advance / ALT screens / toggle or increase a value; hold: fast scroll |
| LIGHT | front, lower right | Backlight |
Turn on / wake
A new unit is in Deep Sleep. Hold SELECT and ADV together for 3 seconds until the Watch screen appears, then let go.
Hold togetherSELECTHold togetherADV.
Manual p. 7The Watch screen is normally shown. Hold MODE to switch to the dive computer (and back to Watch).
HoldMODE
Manual p. 13On the dive surface screen, press ADV (forward) or MODE (back) to scroll the menu: ALT screens, PLAN, LOG, SET FO2, SET ALARMS, SET UTILITIES, SET MODE…
PressADV.PressMODE
Manual p. 25Press SELECT to open the item shown. Hold SELECT to step back; hold MODE to leave the menu.
PressSELECTHoldSELECTHoldMODE
Manual p. 25After 10 minutes on the surface without a button press it goes to Standby. Press a button to wake it.
Manual p. 25
Date and time
The clock and date are set in Watch mode, not in the dive menu (p. 16).
On the Watch screen, press ADV to scroll the Watch menu to SET TIME, then press SELECT.
PressADV.PressSELECT
Manual p. 13Date format: press ADV to choose M-D or D-M, then SELECT. Hour format: choose 12 or 24, then SELECT.
PressADV.PressSELECT
Manual p. 16Default Time (HOME or AWAY) and Alternate Time come next. Press SELECT to keep them.
PressSELECT
Manual p. 17Time of day: press ADV to increase or MODE to decrease the hours, then SELECT. Do the same for minutes.
PressADV.PressMODEPressSELECT
Manual p. 17Date: set the year, month and day in turn with ADV or MODE, pressing SELECT after each.
PressADV.PressMODEPressSELECT
Manual p. 18
Units (m/ft, °C/°F)
One setting (MET or IMP) changes all units together (p. 31).
On the dive surface screen, press ADV until SET UTILITIES appears, then press SELECT.
PressADV.PressSELECT
Manual p. 30Press SELECT to go past H2O Activation to UNITS.
PressSELECT
Manual p. 31Press ADV to choose MET or IMP, then press SELECT to save.
PressADV.PressSELECT
Manual p. 31
Water type (salt/fresh)
Not available on this computer
The manual describes no salt/fresh water setting: Set Utilities lists H2O activation, units, deep stop, safety stop, algorithm, conservative factor, Bluetooth, backlight and sampling rate only (pp. 30–34).
Dive mode (Air / Nitrox / Gauge)
On the dive surface screen, press ADV until SET MODE appears, then press SELECT.
PressADV.PressSELECT
Manual p. 34Press ADV to choose NOR (normal air/nitrox computer), GAU (gauge) or FRE (free diving). Press SELECT to save.
PressADV.PressSELECT
Manual p. 34Warning: after a dive in Gauge mode there is no deco or oxygen calculation until a 24-hour surface interval has passed. Do not use GAU unless your instructor says so.
Manual p. 34
Nitrox O₂% and ppO₂ limit
Gas settings go back to Gas 1 = Air and Gas 2 = OFF when 24 hours pass without a dive. After a nitrox dive, Air cannot be chosen again for 24 hours (p. 28). A note on p. 28 says PO2 is set in Set Alarms, but the Set Alarms menu has no PO2 item (pp. 29–30) and the p. 28 text and diagram set it here, after the O2 %.
On the dive surface screen, press ADV until SET FO2 (SEt F) appears, then press SELECT.
PressADV.PressSELECT
Manual p. 28Gas 1 O2 %: press ADV to increase or MODE to decrease (AIR or 21–100%). Press SELECT to save.
PressADV.PressMODEPressSELECT
Manual p. 28Gas 1 PO2 alarm: press ADV or MODE to set it (it starts at 1.60 for nitrox), for example to 1.40. Press SELECT to save.
PressADV.PressMODEPressSELECT
Manual p. 28Gas 2 screens follow. Gas 2 is OFF by default; press SELECT through them for a single tank.
PressSELECT
Manual p. 28Check the surface screen: it shows the gas number and NX when nitrox is set.
Manual p. 25
Conservatism / personal setting
On the dive surface screen, press ADV until SET UTILITIES appears, then press SELECT.
PressADV.PressSELECT
Manual p. 30Press SELECT to go past each item until ALGORITHM appears. Press ADV to choose DSAT or Z+, then SELECT.
PressSELECTPressADV.
Manual p. 32CONSERVATIVE FACTOR is next: press ADV to choose ON or OFF, then press SELECT.
PressADV.PressSELECT
Manual p. 33Z+ gives shorter no-deco limits than DSAT. CF ON shortens them further, as if you were 915 m (3,000 ft) higher.
Manual p. 21The algorithm cannot be changed for 24 hours after a dive unless Desat time has reached 0:00.
Manual p. 32
Altitude
Altitude is detected automatically; there is no manual altitude setting (p. 58).
Nothing to set: it measures air pressure when switched on and every 15 minutes while dry.
Manual p. 58It adjusts by itself for altitudes from 916 m (3,001 ft) to 4,270 m (14,000 ft), and does not work as a dive computer above that.
Manual p. 58To see the altitude level, scroll to ALT 2 on the dive surface screen with ADV. It shows EL2–EL7, or blank at sea level.
PressADV.
Manual p. 26
Audible alarms (depth / time)
On the dive surface screen, press ADV until SET ALARMS appears, then press SELECT.
PressADV.PressSELECT
Manual p. 29Audible alarm: press ADV to choose ON or OFF, then SELECT. Leave it ON.
PressADV.PressSELECT
Manual p. 29Depth alarm: press ADV or MODE to choose OFF or 10–100 m (30–330 ft), then SELECT.
PressADV.PressMODEPressSELECT
Manual p. 29EDT (dive time) alarm: choose OFF or 10–180 minutes with ADV or MODE, then SELECT.
PressADV.PressMODEPressSELECT
Manual p. 29TLBG (nitrogen) and DTR (OFF or 5–20 min) alarms follow; set them the same way.
PressADV.PressMODEPressSELECT
Manual p. 30An alarm beeps 10 times and a light on the side flashes. Press SELECT to silence it.
PressSELECT
Manual p. 23
Reading the log after a dive
Quick look: press ADV once on the dive surface screen for ALT 1 (last dive: max depth, dive time, dive number).
PressADV.
Manual p. 25Full log: press ADV until LOG appears, then press SELECT.
PressADV.PressSELECT
Manual p. 27Step through dives (date and start time) with ADV or MODE. Press SELECT to open one.
PressADV.PressMODEPressSELECT
Manual p. 27Press SELECT for each page: max depth, dive time, surface time, altitude, lowest temperature, ascent rate; nitrox dives add O2 % and max PO2.
PressSELECT
Manual p. 27The log keeps the last 24 Norm and Gauge dives. Free dives are not in the log.
Manual p. 27
Battery
A solid battery icon is a warning: the computer still works but the backlight is off. Do not dive with a low battery.
Manual p. 22A flashing battery icon is an alarm: in dive mode it drops back to Watch time. Change the battery.
Manual p. 22It uses one 3 V CR2430 lithium battery, changed with the Geo 4.0 Battery Kit. Settings are kept during the change.
Manual p. 57After a change, switch it on, check the display is clear, and check all settings before diving.
Manual p. 58
What the main screen shows
On the surface: surface time, time of day, gas number and dive number. NX shows when nitrox is set; CF when Conservative Factor is on.
Manual p. 25In a dive: depth, max depth, dive time, gas number and Dive Time Remaining (no-deco or O2 minutes, whichever is shorter).
Manual p. 37The left bar shows ascent rate. Above 9 m (30 ft) per minute all segments flash with SLO.
Manual p. 21The right bar (TLBG) shows nitrogen loading. The fifth segment means decompression.
Manual p. 21Press ADV in a dive for time and temperature, and for nitrox the O2 saturation and PO2.
PressADV.
Manual p. 37
Pre-dive check
Tick each item before you get in the water.