The pelican is an adaptable bird: built for diving for fish, it will happily consume any other flesh it can cram into its long bill. One caused a sensation in St James’s Park a decade ago by .

The bird is an appropriate symbol for , the 165-year-old maritime services company. Born as a shipping business, to survive it has evolved over the past 15 years into a seller of services to the oil and gas, energy and maritime industries.

Its most recent buy is Return to Scene, a 3D imaging company that played a role in the that determined 96 Liverpool football fans were unlawfully killed. Its software was used to recreate Hillsborough stadium as it was in 1989 so jurors could understand the police mistakes that allowed hundreds to be crushed in terrace pens at an FA Cup semi-final.

Fisher paid £1.9m for the business after its parent, SeaEnergy, went into administration, a victim of the low oil price that has devastated the oil and gas sector.

Nick Henry, chief executive, says is always on the search for such tasty titbits, which build up expertise in profitable niches. Return to Scene’s main work is modelling oil rigs so maintenance engineers can see what job needs doing before they arrive in order to minimise expensive time spent offshore.

Fisher’s share price took a plunge with the oil price last year, falling a third between June and November after profits dropped.

It has had to lay off a third of its oil and gas workforce, 200 people, in Aberdeen and Norway.

But the City has finally given Fisher credit for the spread of its business, Mr Henry says. First it was seen as a shipping company, and took a pasting in 2008 when world trade slumped. Then it was seen as an oil and gas group.

The shares are back above the January 2015 high of £13.99 and also above their level on June 23, pre-Brexit. Revenue and profits slipped slightly in the full year to £438m and £46m respectively (£449m and £48m).

Fisher now has four divisions. It diversified under first who retired in 2012, and then Mr Henry, both former P&O executives.

As well as shipping and maritime support, it has a defence arm and a specialist technical division, which works in the nuclear and other industries. A recent contract was checking that the repair to the crack in the Forth Road Bridge was robust enough to reopen it.

“We are doers. We are not lobbyists. We don’t influence government decisions. Our IP is in people’s brains,” Mr Henry says.

Take the nuclear industry. Fisher, based in Barrow-in-Furness, where , does not have a view on how quickly old reactors should be decommissioned and waste treated.

But it has some clever ideas on how to do it. It sent a robot to Japan to help with the Fukushima nuclear accident clean up as it is a world leader in remote handling, allowing irradiated parts of plants to be reached.

Fisher has also come up with a novel way to dismantle reactor cores, which has won it a four-year, £60m contract with Magnox Limited to decommission the largest of the reactor cores constructed on the site in Winfrith, Dorset.

The challenge is how to do so while maintaining the protective casing around them. It has pioneered a “salami slice” method, where slices are taken off the top by a robot as it is pushed gradually through the top of the casing.

The parts are then cut up again and buried in concrete.

There are 20 more UK reactors to dismantle. “We go for those niche areas where the margins are big,” Mr Henry says.

Another neat line is in James Bond-style miniature submarines. These are used to monitor underground oil and gas infrastructure or to rescue sailors from submarines. Its latest job is a £193m contract for the long-term provision of submarine escape and rescue for the Indian Navy. The two craft will cost £83m while the rest is a 25-year maintenance contract.

Two-thirds of revenues come from outside the UK, but Mr Henry does not believe Brexit is a problem. Its customers are in places such as Australia, Azerbaijan and Angola. “We do not do a lot of business with the EU so we don’t anticipate much impact.”

The money it makes does flow back to the UK. There have been 21 years of rising dividends. About 25 per cent of the shares are held by the original Fisher family trust, which distributes its dividends to seafaring charities.

Fisher is that rare British company that combines technical and financial engineering successfully.