Edinburgh residents who live near Leith Docks may well be wondering why four giant ships - one of them almost skyscraper-sized, and several with helipads - are currently visiting the capital.
The quartet of huge vessels are called MSV Seawell, DSV Deep Discoverer, MSV Well Enhancer and pipe laying vessel the Seven Navica.
The MSV Seawell is a massive ship was first built in 1987 as a diving support vessel that features a towering, purpose-built derrick over a 7m x 5m moonpool.
Moonpools are openings in the floor or base of the hull that give access to the water below, allowing researchers to lower instruments into the sea.
The 114-meter vessel carries out subsea oil well intervention jobs, which involve diving down to do work on oil or gas wells during or at the end of the wells' productive lives. Subsea well intervention offers many challenges and requires much advance planning.
Nearby you'll find the humongous MSV Well Enhancer, a 10,000+ ton, 132m long well intervention and diving vessel.
The ship features an advanced intervention tower with generous deck space. It also has a 100+ ton crane, an 18-man saturated dive team, a 900+ foot diving bell and 550+ sq. ft. of moonpools.
One particularly unusual-looking member of the big boat squad looks like it has a wheel on its back - that vessel, the Seven Navica, is a cable laying ship built in 1999.
It can install cables at water depths of up to 2000m. It is owned by offshore company Subsea 7, who own much bigger ships like Seven Borealis, a truly huge pipelay and heavy lift vessel pictured below.
Last but by no means least, we have Deep Discoverer, a much newer offshore supply ship that was built in 2019 and is sailing under the flag of the Bahamas. It was found to have a virus outbreak on board back in April and was forced to go into quarantine.
Owners TechnipFMC said there were two symptomatic cases of Covid-19 and “a number of positive asymptomatic cases” on board its Deep Discoverer diving support ship, reported industry news outlet Energy Voice at the time.
