The O'Dive measures bubbles in the clavian vein and combines this measurement with details of the dive profile and breathing gas. The result is a tool that allows divers to change their diving to create fewer bubbles and less risk with small changes to deco, hyrdation, sleep or breathing gas.

The course includes a brief history of deco, plus an explanation of how doppler measurement works. The proof of the pudding is linking the O'Dive to a users phone and taking live personal measurements after a dive. O'Dive technician can be taken by any diver as a diving or dry course, but is a perfect accompaniement to Deep courses and higher, complimenting the emphasis in these courses on deco knowledge and good diving practice.

It's ideal for for archaeology, science, survey or just telling the story of your dive with a fascinating rotatable zoomable model. The IANTD Diving Skills for Photogrammetry course introduces:

• The concepts of photogrammetry
• Cost-effective camera and lighting options
• Safe diving skills such as buoyancy and propulsion
• Survey techniques
• Data processing and model creation

The course progresses from objects on a table to actual underwater targets, getting you going for photogrammetry projects of your own. You don't need to own your own camera and lighting equipment to take this course.

Sidemount is easier on the back and allows more freedom. The IANTD Sidemount specialty course offers indepth attention to rigging to maximise these benefits, plus self-rescue skills. Shutdowns, out or gas drills, cylinder removal and replacement, buoyancy and propulsion all contribute to making happy confident sidemount divers able to take on more demanding dives.

Sidemount diver doesn't offer any depth progression by itself but can be taken in conjunction with the deep speciality.

Luckily the solutions are simple. The IANTD Action Camera Diver works through both camera skills (preparation, planning and shot selection), plus diving skills (gas planning, buoyancy, steadiness and positioning).

We bring all of this together underwater to help you get the shots that you can anjoy by themselves or edit into social media entertainment gold. We can offer advice on types of action camera or lighting rigs to help you to achieve your action camera filming ambitions.

The underwater world comes alive at night. Nocturnal creatures appear on reefs, while wrecks take on a whole new life. Illuminated only by torch, your attention is focussed on only what is lit, which means we often see in far more detail than when distracted by those pesky vistas of day diving. Diving in the dark is also an essential skills for deeper technical diving beyond the light zone.

The night diver course is a solid foundation in the differences of night diving, use of torches for communication, lighting systems and maintaining safe diving practices in a more challenging, but rewarding environments. This is a key part of your 'fully rounded diver' status.

Skills for wreck diving include awareness of new hazards, dive planning and buoyancy control. Observation skills are also a key part of enjoying wreck diving - discovering artefacts or objects that tell the story of the wreck can often shed new light on the mysteries behind the wreck.

Every wreck has three stories - the ship and cargo, the events that lead to her sinking and her later colonisation by ocean life. The IANTD Wreck Diver course is the entry level wreck course for non penetration wreck diving, leading onto more advance wreck penetration and technical wreck exploration.