I dive regularly from Puerto del Carmen and one thing I never skip is a careful packing and pre-dive routine — especially for a single-tank nitrox deep dive. Nitrox lets you extend no-decompression time, but it also adds checks and responsibility. Below I share the exact kit I pack, the tests I run on the nitrox tank, and the pre-dive drills I follow with my buddy to make sure the dive is safe, efficient and enjoyable.
Where I’m diving from and what I mean by “deep”
When I say a one-tank nitrox deep dive from Puerto del Carmen, I typically mean shore or small-boat dives to 28–40 metres where we remain no-decompression (or planned short deco) on a single nitrox cylinder. Locations around Playa Chica, the Außen wall sites and some of the deeper pinnacles off the harbour can fall into this category. These dives require precise gas analysis, correct planning (incl. PO2 limits) and thorough equipment redundancy for comfort and safety.
Packing checklist — what I bring and why
| Item | Why / What I test |
|---|---|
| 1x 12–15L steel/aluminium tank with nitrox (EANx) | Appropriate volume for deeper single-tank dives; I check fill pressure and label (oxygen content) and ensure cylinder visual inspection is current. |
| Nitrox analyzer | Non-negotiable — I verify the oxygen percentage on-site and record it. I also test the analyzer on a known-air cylinder before use. |
| Regulator set with nitrox-compatible first stage | Stainless or environmentally sealed first stage rated for oxygen service if needed; grease-free connection. I inspect hoses and mouthpiece. |
| Backup second stage / octopus | Ready for buddy or as back up in an out-of-order primary. I breathe-check both second stages on surface. |
| Computer set (primary + backup or dive computer + bottom timer) | Programmed for nitrox mix; I verify PO2 limit (commonly 1.4 bar for working portions) and ensure both are synchronised on time and gas settings. |
| SPG or integrated gauge | Confirm pressure and leak-free. Record starting pressure. |
| Wing/BCD with reliable dump valves | Good lift for planned weights; inspect inflator hose for leaks. |
| Weights (trim and emergency)\td> | Fine-tune so you are slightly negative at surface in heavy kit, neutral at depth. I use a small spare weight or clip-on as emergency ballast if needed. |
| DSM BCD/Surface marker buoy (SMB) + reel | Essential for deeper ascents and boat pick-ups; test line and reel drag before water entry. |
| Personal safety: knife, whistle, mirror | Standard surface-safety kit tucked into pockets or leg strap. |
| Torch (primary) + backup | Good for low-light or overhangs; confirm batteries and straps. |
| Spare mask and fins | Stored on the boat or shore bag — I prefer spares easily accessible for short-notice swaps. |
| Thermal protection (3/2mm to 7mm depending on season) | Lanzarote can be cooler at depth; choose suit thickness accordingly and test for freedom of movement. |
| Logbook, dive plan printout, local contact | Hard copy of the plan, surface interval and emergency contacts — always left with surface support. |
On-site nitrox testing protocol
I treat nitrox like a responsibility. Quick steps I run through every time I pick up a nitrox cylinder:
- Visually inspect the cylinder label and valve — does it say the mix and who filled it? If something looks off, don’t dive it.
- Turn on and zero the analyzer (follow manufacturer instructions). I always test it on atmospheric air first to confirm it reads ~21% O2.
- Analyze the cylinder at least twice, taking readings from the valve after a short purge — record the percentage and the time. If two readings differ by >0.5% I repeat until stable.
- Calculate maximum operating depth (MOD) for the planned PO2. I usually use a PO2 ceiling of 1.4 bar for working phases and 1.6 bar for short exposures only if the dive plan accounts for it.
- Label the cylinder with the exact % O2 and MOD where required by local rules.
Pre-dive planning and numbers
I always plan dives conservatively. For a 32% nitrox mix, for example:
- MOD at PO2 1.4 bar = (1.4 / 0.32 - 1) × 10 = ~33 metres.
- Check dive tables or computer settings to ensure your no-deco time is adequate for the planned depth and bottom time.
- I set my dive computer to the exact mix. If my backup is a non-mix computer, I plan to stick within the most conservative no-decompression limits and monitor ascent carefully.
We also agree on turn pressures rather than turn times when deeper profiles are expected. I usually set a conservative turn pressure (e.g. start ascent at 50–80 bar depending on consumption and contingency plans).
Buddy and pre-dive drills
Before we enter the water I run a deliberate sequence with my buddy:
- Kit visual and functional check: both second stages, octopus, SPG, inflator, and leaks.
- Gas confirmation: both divers announce each other’s cylinder mix and analyze readings aloud. I’ll say, “I have 32% — MOD 33m” and my buddy repeats it back.
- Computer settings: confirm both computers are set to the right O2% and time; sync watches or agree on a common timepiece if needed.
- Weight check: do a quick surface float assessment to confirm we’re properly weighted.
- Emergency procedures: rehearse out-of-air protocols (donor position, ascent rates), SMB deployment, and lost-buddy separation plan (time/marker before surface).
- Navigation and depth profile: agree on maximum depth, route, and time or pressure to start ascent. Agree on a maximum penetration or approach distance from the shore/boat.
During the dive — focus points
Some practical behaviours I keep during the dive:
- Monitor PO2 and your no-decompression limits regularly. If you approach conservative limits, start ascent early.
- Watch gas consumption. At depth your breathing rate rises; if your buddy’s consumption spikes, call the drill early.
- Trim and buoyancy — maintain a stable horizontal trim to reduce exertion and gas use.
- Communicate frequently. Simple checks (“OK?” “Air?”) every 5 minutes save misunderstandings later.
- If any equipment behaves oddly (free-flowing reg, computer alarms), abort the bottom phase and ascend according to the emergency procedures discussed pre-dive.
Surface and post-dive checks
On the surface I always:
- Confirm both divers are OK and collect the SMB if used.
- Log the exact mix, start/end pressures, bottom time and max depth immediately — record any issues or unusual consumption.
- Inspect gear for salt, sand or damage and flush regulators appropriately.
- If oxygen first aid was used or there was a rapid ascent/deco obligation, notify the dive centre and follow local incident reporting procedures.
These routines may seem detailed, but after hundreds of guided dives I’ve found they become natural and significantly reduce risk. Nitrox gives us extra bottom-time or safety margin, but only if you respect the math, test the gas, and run the drills every single time. If you’d like, I can share a printable checklist or a downloadable nitrox calculation chart tailored to Lanzarote depths and typical fills from local shops.
