Keeping Britain’s seaways safe for ships is the daily work of the 500-year-old organisation Trinity House.

The captain of the mighty Trinity House Vessel Galatea guides her expertly into position by the 15m-high Class One buoy, which is about to be disengaged from its seabed anchor of five tons of iron ballast. The buoy is about to get its annual scrub and inspection. On Galatea’s heaving deck, crewmen prepare the strops and crane. They hook the buoy and its ten tonne bulk rises slowly out of the sea, crusted in barnacles and bearded with weed. An hour later the buoy goes back in, serviced and clean.

Keeping Britain’s seaways safe for ships from around the globe is the daily work of the 500-year-old organisation Trinity House. THV Galatea and her two sisterships might be called on to clear a wreck. A helicopter, directed from the Harwich Planning Centre, will be sent to land on a lighthouse, bringing engineers to check its bank of high-tech gadgetry. In the Navigation Department in London, staff study electronic charts and shipping movements to advise on the siting of offshore wind farms.

Trinity House gets on with its work efficiently and quietly, so much so that most yachtsmen have little idea what a huge role this ancient institution plays in our easy enjoyment of weekends and holidays afloat. Not many people know that Trinity House is responsible for enhancing and re-broadcasting GPS signals from US satellites to produce extremely accurate DGPS.

It all started with pilotage. In 1514 Henry VIII granted a mariners’ guild a Royal Charter to regulate the pilots who guided ships among the Thames’s shifting shoals. London was going from strength to strength as a merchant port and everyone wanted to profit. The guild’s mission was to stop chancers and ne’er-do-wells passing themselves off as pilots endangering valuable cargoes and sailors’ lives. Today, Trinity House examines and regulates all the deep sea pilots operating in Northern Europe.

Queen Elizabeth I increased its powers in the 1566 Seamarks Act, enabling it to set up ‘so many beacons, marks and signs for the sea . . . whereby the dangers may be avoided and ships come unto their ports without peril’. That Act still exists today, and Trinity House is responsible for all 63 lighthouses and all the major sea-marks around the coasts of England, Wales, the Channel Islands and Gibraltar. It also performs the mind-boggling task of annually checking the position of every single buoy and marker post in England and Wales – in every river, harbour and bay, however large or small, working with the Admiralty to keep charts up to date.

The Brotherhood

In the 16th Century, guilds ran much of the City of London’s commerce. Trinity House is highly unusual in retaining the guild structure for its corporate arm, which manages £6 million of charitable works funded from lands and estates it has owned for centuries.

If you stand outside the stately London headquarters at Tower Hill on the annual Trinitytide, you may catch a glimpse of the Trinity House Brotherhood. A procession emerges, led by the Messenger, dressed in purple, and carrying the Corporate Mace. Following two-by-two are the Master (usually royalty, currently HRH Princess Anne), the Deputy Master (currently the ex-Captain of the QEII, Ian McNaught), 31 Elder Brethren and many of the 300 Younger Brethren (drawn from from all walks of British maritime life).

The procession heads for St Olave’s church for a private service then returns to the House and the magnificent court room. Under the gaze of Henry VIII from one end and Queen Elizabeth I from the other, that year’s Master and Deputy are sworn in. Each person takes a sip of wine from two 17th Century silver steeple cups in what is surely one of the maritime world’s most ancient annual ceremonies.

More than a museum

Yet the House is more than a museum. On the ground floor in the modern navigation directorate, I met the director of navigational requirements, Captain Roger Barker. He has observed a worrying trend which indicates that lighthouses, buoys and deep-sea pilots will be needed for years to come. Shipping is increasing, crews are getting smaller and there is complacency among some ships’ officers who, says Barker: “Make use of data on a memory stick with the route they used on a previous voyage – following the red line with misguided confidence.”

Paradoxically, the introduction of electronic navigation has led to the need for more, not fewer, marks. “There are places in busy coastal sea lanes,” Barker explains, “where the near-misses we see on ships’ AIS tracks are becoming increasingly concerning. As the mariner takes himself closer to danger, relying on electronic charting and positioning, it is necessary to install additional marks in danger spots. Modern technology also means that the lights we deploy on buoys are much easier to see – for those keeping a sensible lookout.”

There’s frailty in satnav too. GPS jammers capable of causing catastrophic outages are on sale online for as little as £30. Recently South Korea suffered a 16-day GPS jamming attack. Trinity House is concerned about the ease with which terrorists could wipe out GPS signals across the Dover Strait. Other systems such as the Russian GLONASS and EU’s Galileo work on similar wavelengths to US GPS and are just as vulnerable.

In response, Trinity House and the General Lighthouse Authorities for Scotland and Ireland are pioneering an alternative system as back-up in case of failure. The new eLoran is a land-based long-wave radio system currently being trialled by ferries in the English Channel. Governments from around the globe are consulting with Trinity House on how to implement eLoran in their own countries.

Technology moves on apace and Captain Barker says the mission of Trinity House is “to deliver a reliable, efficient and cost effective ‘aids to navigation service’ for the benefit and safety of all mariners”. But the ancient rituals of the Brotherhood will remain. Royals yet unborn will sup from those silver steeple cups when Masters many years hence are sworn in.

This is an extract from a feature in Yachting World September 2014 issue