The huge price tag on a platform supply vessel (PSV) can be explained by its upcoming conversion into a cable-layer.

An offshore shipping source told TradeWinds that Oslo-listed owner SD Standard Drilling's 5,150-dwt Standard Princess (built 2008) is another example of an oil and gas support ship leaving the sector.

The cable-layer market is said to be "very hot right now", as ships are in demand for offshore wind farm work, among other things.

The Standard Princess fetched $10.3m from an undisclosed buyer, against a VesselsValue assessment of its value of $6m.

The PSV had "been for sale a while and no offshore player was interested at those levels", the source said.

Cyprus-based Standard Drilling, controlled by Norwegian tycoon Oystein Stray Spetalen, said the proceeds from the sale and any future divestments of the offshore fleet will be directed towards "more liquid investments within Standard Drilling's core sectors".

The company, which is looking to move more into renewables, will book a gain of $2.3m from the transaction.

The large PSV was built at Aker Brattvaag in Norway and has 1,060 square metres of deck space.

The shipowner will be left with seven PSVs: two large units that are 100% owned and five medium-sized vessels in which it has a 28% stake.

TradeWinds has also reported that another large PSV sold by Havila Shipping is to have a second life as a yacht.

Brokers said the 4,900-dwt Havila Crusader (built 2010) will be converted under new ownership.

Oslo-listed Havila said earlier in November that the vessel had been sold. VesselsValue listed the new owner as Alegranza Shipping Corp of Panama.

Many offshore support vessels have left the oil and gas business in an over-tonnaged North Sea market.

Some have moved into the aquaculture, renewables or charity sectors, or been turned into emergency response vessels.