The weather on the North Sea

Generally speaking the weather limits for wreck diving are:

• maximum 4 beaufort. See also the beaufort scale.
• maximum wave heights of 1 meter

This has to do with the safety of the wreckdiver, especially when the dive is finished:

• Climbing back on board can be dangerous when the ship is rolling and violently moving the stairs in and out of the water.
• Whenever there is an emergency, rescueing a victim on the North Sea, will always be hazardeous and the weather conditions will be a delaying factor.
• High waves, make it difficult for the wreckdiver to have a good control over the decompression depth; this can lead to decompression illness or accident.

Tidal currents

Tidal currents in the North Sea can be very strong (up to 17 knots in some areas !)
It is the skipper's responsibility to plan the dive on the wreck such that the tidal current is minimal.
This is usually the case at the turning point of the tide.
Ideally, midweek diving trips on the north sea are planned such that neap tide happens in the middle of the week.

Underwater visibility

It is irresponsible to let divers down, when the visibility on the wreck is poor (<1meter).
The wreckdiver can get stuck in a net or enter the wreck without even noticing.
Before the dive, the skipper should measure the visibility.
It is possible that the visibility measured by the skipper is different from the one at the wreck. In this case, the diver must decide by himself to stop the dive and return to surface.

Certificates

Most organisations require a minimum of experience before allowing wreck diving and combine
this with other conditions.
The NELOS, Belgian (flemish) federation requires following conditions:

• at least 2* diver (min. 20 dives, all depth qualifications)
• max. 4 beaufort
• required material: rescue jacket, torch, knife and surface marker buoy
• it's not allowed to make decompression dives on the North Sea.