Advanced technical diving to 50 metres
PADI Tec 50: technical diving
Course description
PADI Tec 50 completes the PADI Tec Deep Diver programme, a path in three parts: Tec 40, Tec 45 and Tec 50. A certificate at this level means the diver has the full skill set of open-circuit technical diving with air, nitrox and oxygen.
The course focuses on planning and carrying out dives to 50 metres with two decompression gases. Adding a second gas is not just an extra cylinder: it is a sharp rise in the complexity of the plan, with two gas switch procedures in one ascent, a higher task load and less margin for error in the order of actions.
The programme covers advanced mission planning, management of several gases, precise control of decompression and responding to complex emergencies. Participants work on deep and decompression profiles, in a full technical kit, in an environment where the diver’s responsibility is at its maximum and the margin for error at its minimum.
The aim of the course is readiness to carry out advanced technical projects independently: deep wrecks, walls and exploration dives. It also gives a solid base for moving on to trimix training.
5-6 training days, depending on conditions, location and the pace of the team.
2 theory sections, 3 practical sessions (skill exercises), 4 training dives on deep and decompression profiles.
4 training dives. We run them with growing complexity of the profile and number of gas switches.
Maximum depth: 50 metres.
Multi-stage and accelerated decompression, with no time limit: the limit is your gas supply.
Bottom gas: air or nitrox. Decompression gases: two, with oxygen content up to 100%.
You can complete the course as PADI Tec 50 Trimix, using trimix with up to 40% helium as the bottom gas.
A maximum of 2 people per instructor: at this level, full control of the training process requires a very small team.
The PADI Tec 50 certificate allows you to plan and carry out dives independently:
- to a depth of 50 metres,
- with multi-stage decompression, with no decompression time limit other than the one that comes from gas planning,
- with two decompression cylinders holding gases with oxygen content up to 100%,
- in a team of divers with the right qualifications.
Tec 50 opens the trimix path: it is a prerequisite for both the PADI Tec Trimix 65 course and the full PADI Tec Trimix Diver course.
- Age: 18 years completed;
- Technical certification: PADI Tec 45 Diver or an equivalent certification from another organisation;
- Rescue certification: PADI Rescue Diver or equivalent. For a qualification from another federation, confirmation of first aid and CPR training from the last 2 years is required;
- Experience: at least 100 dives recorded in a logbook, including at least 20 on nitrox deeper than 18 metres and 15 to a depth of 30 metres or more;
- Health: a current medical statement (signed by a doctor within the last 12 months).
At this level we also require current dive insurance that covers decompression diving and treatment in a hyperbaric chamber.
Main configuration
- twinset with an isolation manifold or a sidemount set: two independent cylinders with a capacity suited to the planned exposures,
- backplate and single-piece harness,
- wing with buoyancy suited to the configuration,
- two independent regulators: a primary on a long hose (about 2 m) and a backup on a bungee around the neck,
- a pressure gauge on each first stage,
- a weighting system chosen for the configuration and exposure.
Decompression cylinders
- two decompression cylinders (typically 7-11 l) prepared for use with oxygen: oxygen cleaning, suitable lubricants and seals,
- a separate regulator with a gauge for each cylinder,
- a harness for each cylinder with double-ended bolt snaps,
- clear marking of the mix and maximum operating depth (MOD): at this level markings are critical, because a mix-up of cylinders means the wrong gas at a stop.
Instruments and safety equipment
- a dive computer that handles multiple gases and a second independent instrument for time and depth,
- backup buoyancy control: a second lift bag, or a dry suit with light cylinders,
- a decompression buoy with a reel or spool of at least 30 m, and a spare buoy,
- two cutting tools placed independently,
- a spare mask,
- a slate for underwater notes with the dive plan and the contingency profile,
- a primary and a backup light.
Additionally recommended
- a dry suit with an undersuit suited to long exposures,
- the decompression software you use for planning,
- your own oxygen analyser,
- a basic set of tools and consumables.
Training fee
The price is set individually, depending on where the course takes place and the logistics.
Registration and certification fee
According to the current price list of the certifying organisation.
Training materials
The PADI Tec Deep Diver package: charged separately, unless you bought it at an earlier level.
Additional costs
Breathing gases (including oxygen and, for the Trimix variant, helium), technical equipment rental, dive logistics, travel, accommodation and meals.
Theory
The theory part has two sections and focuses on the complexity that a second decompression gas brings:
- mission planning: building the main plan and contingency plans, and critically reviewing the generated profiles;
- strategy for choosing decompression gases and the order of switches during the ascent;
- gas management with two decompression cylinders: reserves and the scenario of losing one of the gases;
- accumulated oxygen exposure during long decompression: monitoring central nervous system and pulmonary dose;
- physiology of deep diving, long stops and the consequences of planning errors;
- the Trimix variant: the effect of helium on narcosis and breathing gas density.
Practice
The practical part focuses on managing a complex dive without losing control:
- workshops on configuring the full kit with two decompression cylinders;
- a sequence of two gas switches in one ascent, confirmed with the team at every switch;
- precisely holding long, multi-stage decompression stops;
- clipping off, handing over and recovering cylinders underwater under full task load;
- complex emergency scenarios: loss of a decompression gas, valve failure, interrupted decompression, a buddy’s problem during a stop;
- dives on deep profiles with full decompression, carried out to a plan you prepare yourself.
The pass criterion is not performing the exercise but repeating it: the skill must be done correctly, calmly, and with position control and situational awareness kept.
FAQ
Projects
Dives with a specific task to carry out: at this level a project is the natural working environment of a technical diver:
- wreck projects: documentation, identification and measurement of sites within 50 metres;
- underwater photography and photogrammetry: working with a camera during extended decompression;
- exploration and mapping: surveying dive sites, working with a line, drawing sketches;
- research and conservation work with institutions that deal with underwater heritage;
- logistical and surface support for deeper projects run by trimix teams.
We pick team members by training level, not by the order of applications. If a project is too early for a given diver, we propose an intermediate path.
Trips
Several days in a row in the same team build experience faster than the same number of dives spread over the whole season:
- the Baltic: wrecks and boat logistics, with a large share of the sites within Tec 50 range;
- trips in Poland: lakes and flooded quarries, good for staying in shape between trips;
- trips abroad: deep wrecks and walls, longer decompression exposures;
- small teams, a dive plan of growing complexity and gas supply agreed before departure;
- a contingency plan that covers the nearest hyperbaric chamber, and instructor support on site.
Before a trip it is worth planning an equipment check, a check dive in the target configuration and insurance that covers decompression diving. We keep the trip calendar separately.
Further training
The natural continuation after Tec 50. The order depends on which direction you want to develop your diving range:
- PADI Tec Trimix 65: the entry into normoxic trimix, dives to 65 metres;
- PADI Tec Trimix Diver: the full trimix training, also available directly after Tec 50;
- PADI Tec 50 Trimix: trimix within your current certification limits, if reducing narcosis is the priority;
- PADI Tec Gas Blender: preparing your own mixes, including helium mixes.
Tec Trimix 65 is not formally required before the full Tec Trimix Diver course, but it shortens it: a diver with the Tec Trimix 65 certificate completes only the three deepest training dives instead of eight, provided they continue training with the same instructor within 6 months.
