Diving & Underwater

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General principle of operation
Diving jobs can take place in tanks or pools, open water or offshore, in all cases the equipment and procedures are usually very similar. Although your job may not involve work in, or under the water, if you are working near water and there is a possibility of any of the crew falling in, diving safety standby may be required.

The Dive Master will undertake very thorough research into the dive, to assess local conditions and facilities. This may be straightforward for a dive in a film studio tank he is familiar with; or it may be much more complex for an offshore dive, off Scotland for example.

Often the Dive Master will undertake a site visit to assess local conditions and to gather local knowledge. In conjunction with earlier meetings with the crew and this trip he will put together a dive plan. Talk it through with him now, because he will be very reluctant to change anything once the dive has started; he will ‘plan the dive and dive the plan’.

There will be three or more divers, even for the smallest job, one of which will always stay on the surface, in a safety and co-ordination role.

There are very strict time limits for how long a diver can stay underwater, this primarily depends upon how deep the diver goes. As a simplification, once a diver has used up his daily allowance he will not go down again; the Dive Master will explain the details to you.

First considerations
Can you afford it?

Find a dive team that knows the facility or area you want to use, it can save you time and money.

What are the weather, tide and visibility conditions likely to be? If you can avoid underwater lighting, do so, it will cost you on a greater scale than surface work.

Everything takes about ten times as long to do underwater, so if the job or parts of it, can be done out of water, do so.

Budget expectations
Diving can be a risky business and it takes a long time to qualify, allied to this the teams operate with a minimum crew of three, there will be research time and possible site visits. This makes the process expensive.

Lighting the job will make the costs jump again.

If artists are involved they will require special assistance underwater and a certain degree of training before they are able to work on the shoot.

On top of this, remember that the simplest tasks take a long time underwater and your divers have limited time in which to achieve them, even in the shallow end of a pool.

Safety is paramount, so paramedics and ambulances may have to be on site and your insurance company may insist on waterproof lighting being used in the surrounding area.

See “problems to watch out for”.

Questions to ask
What’s the Dive Master’s opinion? – It is important as he will have the final say on what does and does not go ahead.
What’s the cameraman’s opinion? – It is important as shooting underwater is nothing like shooting on land.
Are weather conditions in the area likely to cause a problem? – Keep checking weather reports in the run up to the shoot.
How long will the job take? Is there anything we can do to reduce this time?

Problems to watch out for and things to do
- Near endless, so be careful.
- Models, props and rigs all work differently underwater and often need to be modified or custom made, this will increase the cost and may require testing.
- The weather and tides can cause all sorts of problems, for example a heavy rainstorm a week before can make usually clear seawater like soup if you are near an estuary.
- If the location is tidal, at what time did you inspect the location? Will the tide conditions be the
same on the day and time you want to shoot?
- The colours of objects change underwater at different depths.
- Objects appear closer underwater and this will alter your lens choices.
- Changing magazines and lenses can take half an hour or more depending upon location.
- Communication is very difficult and not necessarily accurate.
- Has the artist been tested underwater in the conditions they will be operating in?
- As a rule, everything is harder than it would be on land, takes much longer and costs a lot more.
And so on...

Know the jargon
Barometric chamber Where to hang out if you have the bends
Bends Nitrogen bubbles in the blood, gathering at joints, causing pain – nasty or fatal.
Due to being under for too long and surfacing without decompression stops
Buddy Divers usually dive in pairs with a ‘buddy’
Decompression stop Stops on the ascent used to prevent ‘bends’ when a diver has absorbed a lot of nitrogen
Dive Master The leader of a dive team
Dive platform The place the divers dive from (boat, jetty etc)
Dry suit Waterproof suit needed in very cold or polluted conditions
HSE part IV The usual level of qualification needed in the UK to work as a diver in media
Hydrophone Usually a loudspeaker underwater to talk to the diver – one way only
Live-aboard Ship where you live and dive from
Offshore Sea
Openwater Lakes, rivers, canals, very sheltered inlet etc
Re-breather Apparatus that lets a diver stay under longer but need special training to use
RIB Rigid inflatable boat – fast inflatable boat
Rip tide Usually occur in particular places, under particular conditions – dangerous, pulls you
away from shore
Safety stop Diver pauses for a time when ascending; a safety measure – see ‘Decompression stop’
Sharks Toothy things – avoid
Shortie Shorts and T-shirt style wetsuit – very warm conditions only
Surface feed The diver is tethered to the surface and is supplied air down a tube
Tables Used to calculate safe dive patterns
Visibility The distance that you can see underwater – at best about 20 meters, usually much less
Wet suit Non waterproof rubber suit worn in most conditions