Mares Puck 4 setup guide
Wrist dive computer with a single button (Bühlmann ZH-L16C with gradient factors). Air, Nitrox (up to 3 gases) and Bottom Timer modes; user-replaceable CR2450 battery and Bluetooth log download.
Buttons
| Button | Where | What it does |
|---|---|---|
| Button | the single button on the case | Short press: next menu / change value / alternate dive info. Press and hold (1 s): enter or confirm; in a dive it turns on the backlight. |
Turn on / wake
The manual has no separate on/off switch: there is only one button. Press = scroll/change; press and hold (1 s) = enter/confirm.
Press the button to switch the Puck 4 on. It always starts in pre-dive mode, ready to dive.
PressButton
Manual p. 9In pre-dive it checks the pressure and starts logging the moment you pass 1.2 m / 4 ft.
Manual p. 7If you get in the water without switching it on, it still starts the dive, but up to 20 seconds late. Switch it on before you enter the water.
Manual p. 13If it stays in pre-dive for 10 minutes with no button press, it switches itself off.
Manual p. 13To leave any menu, press the button until bACK appears, then press and hold for about 1 second.
PressButtonHoldButton
Manual p. 7
Date and time
In pre-dive, press the button until SET appears, then press and hold for 1 second to open it.
PressButtonHoldButton
Manual p. 9Press to scroll to CLOCK, then press and hold to open it.
PressButtonHoldButton
Manual p. 11Press to change the blinking value. CLOCK covers the time format (12/24 h), the time and the date.
PressButton
Manual p. 11Press and hold to confirm each value and move to the next.
HoldButton
Manual p. 7To leave, press until bACK appears, then press and hold.
PressButtonHoldButton
Manual p. 7
Units (m/ft, °C/°F)
Open SET (press until SET, then press and hold).
PressButtonHoldButton
Manual p. 9Press to scroll to UNITS, then press and hold to open it.
PressButtonHoldButton
Manual p. 11Press to choose metric (m and °C) or imperial (ft and °F), then press and hold to confirm. Depth and temperature units change together.
PressButtonHoldButton
Manual p. 11
Water type (salt/fresh)
Open SET, press to scroll to WATER, then press and hold to open it.
PressButtonHoldButton
Manual p. 10Press to choose SALt (sea), FRESH (lake) or EN13319, then press and hold to confirm.
PressButtonHoldButton
Manual p. 10A wrong water type only changes the shown depth by up to about 3%. Decompression is calculated from pressure, so it is not affected.
Manual p. 10
Dive mode (Air / Nitrox / Gauge)
Bottom Timer mode is not suitable for a student who needs no-deco times. Check the mode on the pre-dive screen before every dive.
Shortcut: in pre-dive, press and hold the button for 2 seconds to go straight to the MODE menu.
HoldButton
Manual p. 7Or open SET and press and hold on MODE.
PressButtonHoldButton
Manual p. 9Press to scroll AIR, NItROX and BOTTOM TIMER (BT), then press and hold to choose one. AIR is the same as 21% oxygen with a 1.4 bar limit.
PressButtonHoldButton
Manual p. 9BOTTOM TIMER shows only depth, time and temperature and does no decompression calculation. Do not count on any alarm in this mode.
Manual p. 9, 12, 16You can only choose BOTTOM TIMER when the computer is fully desaturated (no nitrogen left from earlier dives).
Manual p. 16After a dive in BOTTOM TIMER, wait at least 48 hours before diving with a decompression computer.
Manual p. 16After an ascent violation or a missed deco stop, the Puck 4 works only as a bottom timer for 48 hours.
Manual p. 16
Nitrox O₂% and ppO₂ limit
The manual does not describe any automatic reset of O2% to 21%: the setting stays until you change it, so check it before every dive. With 80% O2 or more, ppO2max is set to 1.6 bar automatically (p. 15).
Open the MODE menu (press and hold 2 s in pre-dive), press to NItROX, then press and hold to choose it.
HoldButtonPressButtonHoldButton
Manual p. 9Press to change the oxygen % (O2%). Watch the maximum operating depth (MOD) change with it.
PressButton
Manual p. 9Press and hold to move to ppO2max, then press to change it (1.2 to 1.6 bar; factory setting 1.4 bar).
HoldButtonPressButton
Manual p. 12Press and hold to save and exit. Holding for 3 seconds saves and exits at any time.
HoldButton
Manual p. 9Before every dive and after changing tanks, check that the O2% on the computer matches the analysed tank.
Manual p. 9
Conservatism / personal setting
The active setting (R0–R3 or GF values) is shown on the pre-dive screen (p. 13).
Open SET, press to ALGO, then press and hold. Press and hold again on MAIN.
PressButtonHoldButton
Manual p. 10Press to choose R0 (85/85, the default), R1, R2 or R3 (50/60), or CUStOM to enter your own GF low/high.
PressButton
Manual p. 10Press and hold to confirm. A higher R number means a more conservative setting, with more safety margin.
HoldButton
Manual p. 10REP and M-dAY (in ALGO) add extra conservatism for repeat dives and several days of diving. While they are active, an M is shown next to the setting.
Manual p. 14
Altitude
Not available on this computer
There is no altitude setting: the Puck 4 checks the air pressure every 20 seconds and adjusts automatically. Mares does not recommend diving above 3700 m / 12100 ft (p. 12).
Audible alarms (depth / time)
In BOTTOM TIMER mode do not rely on alarms: the manual says on p. 9 and p. 12 that all are off except low battery, but on p. 16 that ascent rate, max depth and dive time still work.
Open SET, press to WARN, then press and hold to open it.
PressButtonHoldButton
Manual p. 10MAX DEPTH: set a depth alarm from 10 m / 30 ft up to just below the MOD, in 1 m / 5 ft steps. It is OFF by default.
PressButtonHoldButton
Manual p. 10DIVE TIME: set 20–90 minutes in 2-minute steps (OFF by default). The dive time blinks at half the time and at the limit; press the button to acknowledge.
PressButtonHoldButton
Manual p. 10NO DECO and ENTERING DECO can be turned ON to warn at 2 minutes of no-deco time left and when a deco stop is needed.
PressButtonHoldButton
Manual p. 10Sound: ALL SILENT in SET turns off the audible alarms. Leave it off so the alarms can be heard.
Manual p. 11
Reading the log after a dive
In pre-dive, press until LOGBOOK (LOG) appears, then press and hold.
PressButtonHoldButton
Manual p. 11First you see StAtS: deepest dive, longest dive, coldest water, total dives and total dive hours.
Manual p. 11Press to scroll through the dives, newest first. Press and hold on a dive to see more details.
PressButtonHoldButton
Manual p. 11To leave, press until bACK appears, then press and hold.
PressButtonHoldButton
Manual p. 11Right after a dive, the post-dive screen also shows a short summary: max depth, lowest temperature, dive time and O2%.
Manual p. 14
Battery
No battery symbol on the pre-dive or dive screen means there is enough charge to dive.
Manual p. 7A steady battery symbol means a few dives are left. Replace the battery soon.
Manual p. 7A blinking battery symbol means the battery is too weak. Do not dive: it will not work as a dive computer and will not switch on under water.
Manual p. 7The INFO menu also shows the battery level.
PressButtonHoldButton
Manual p. 7It uses a CR2450 battery that the user can replace; Mares suggests having it done at an authorised Mares centre.
Manual p. 17
What the main screen shows
Pre-dive screen: shows the conservatism (GF) setting, the active gas and its MOD.
Manual p. 13During the dive: current depth, temperature and max depth taking turns, NO DECO time and dive time.
Manual p. 13In a deco dive, the NO DECO time is replaced by the deepest stop depth, its time and the total ascent time.
Manual p. 13Ten-segment nitrogen bar graph: the more segments lit, the closer you are to the no-deco limit.
Manual p. 13Ascent speed shows as a number and as six segments on the left; if you go too fast it beeps and shows SLOW.
Manual p. 12Press the button to change the bottom-right field: O2%, CNS, ppO2, GF setting, time of day, stopwatch.
PressButton
Manual p. 14Press and hold the button during the dive to turn on the backlight.
HoldButton
Manual p. 7
Pre-dive check
Tick each item before you get in the water.