Diving Lore

Offshore Activity

Offshore Vessels

Offshore Vessels work in some of the most hostile parts of the world, they are among the main players in oil and gas projects offshore, it is the quest for crude oil and other hydrocarbons which sees them rising in demand as the race for resources continues.

The Offshore Vessel Review

Listed below are the offshore vessels types and a review of those named. If there is a live link to them then they have been reviewed and their good and bad points are discussed. (click to view).



The trend of using FPSOs (drilling ships) has meant that commercial divers tend to operate from massive Dive Support Vessels (DSVs) which roam the seas carrying out essential work underwater for platform and vessel alike.

The FPSOs that extract the hydrocarbons which literally powers the modern world. Without them the world we know would literally grind to a halt and civilisation would be on the verge of the paradigm shift.
They tend to be very long vessels operating in a static location for long periods. They require a permenent workforce to remain onboard for oil processing to be carried out. Oil tankers often use these to collect crude oil and gas for onward transportation elsewhere.

The advantages of FPSOs is that for marginal oil fields and deep water fields they can turn a profit where a static offshore platform would struggle. When the oil runs dry at one reservoir the FPSO can move somewhere else


DSV - Bibby Sapphire

DSVs or Dive Support Vessels are seeing increased use offshore, they utilise commercial air / Saturation divers and ROVs to complete offshore projects.

In the old days the vessels would be converted supply vessels or Pipe carriers. In poor weather though they were less than ideal. By the 1980s a number of DSVs had emerged and completed important work in the North Sea. They also carry out cable laying.

The bread and butter of DSVs is saturation diving at depths greater than 50m. Using a heliox mix (nitrogen and oxygen) vast depths can be reached. In the North Sea the average depth of operations tended to be 140 - 150 metres. The deepest reached so far is a massive 300 metres!
They are amongst the most well travelled vessels in the Oil and Gas Industry. Equipped with Dynamic Positioning for near rock-steady stability using GPS or laser-reference points.

Although semi-submersible DSVs were 'in-vogue' in the past they are slow to move between stations with mono-hulled DSVs tend to be the norm these days.

Since 2008 a number of new DSVs have been commissioned and launched with more to follow, this followed the price boom of crude oil and gas.

Grampian Sprite

Bibby Sapphire

Jack-Up Barges, Semi-Submersibles / Flotels


Jack-Up Barges, Semi-Submersibles / Flotels are also important in augmenting a platforms workforce. Ocean going vessels in their own right they too play their part in the offshore world. Some of these are versitile structures, carrying out drilling projects and Flotel work depending on the situation. Although usually anchored to sea-bed they also tend to have Dynamic Positioning for work in deep water locations.

Borgholm Dolphin

Safe Astoria

Safe Bristolia

Safe Britannia

Safe Caledonia

Safe Concordia

Safe Esbjerg

Safe Hibernia



Safe Lancia

MSV Regalia

Safe Regency

Safe Scandinavia

 Sedco 706

Jack-Up Barge

Irish Sea Pioneer


Stand-by Vessels

Stand-by Vessel - Lowland Cavalier

Stand-by Vessels are often an unsung hero of the North Sea and beyond. They roam and watch over a platform from a distance, making sure all is well and if any personnel fall overboard are rescued ASAP. In the event of a major disaster they will close in and tackle a blaze as a fireship while launching rescue craft.

Lowland Cavalier

Supply Vessels

Although limited / specialist supplies can be flown out in a hurry via helicopter it is the Supply Vessel which is the king of re-supply. The primary method in which an offshore installation receives the bulk of it's supplies are from Suppy Vessels. Usually called 'the supply boat' or simply 'the boat'. Anywhere you see an offshore platform in the sea, a supply vessel won't be far away. Toing and froing, back and forth with kit either for 'the beach' or offshore. Equipment being back-loaded to the mainland, vital pipework and large containers containing other kit are just some of the stuff that shuttles about to these vast vessels.

Knock Nevis

Skandi Marstein

Skandi Commander



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