9 Wee Facts About the Irish Sea

The Irish Sea is the stretch of water that separates Ireland from Great Britain, tucked between Scotland, England, Wales, and the east coast of Ireland. It covers roughly 18,000 square miles, and depending on who you ask it goes by the Manx Sea or gets folded in with the Celtic Sea to the south. It is easy to treat it as the gap you cross to get somewhere else. Look closer, in a pub or on the bathymetry of a wood chart, and it turns out to be one of the more interesting bodies of water in Europe. Here are nine wee facts to prove it.

1. The Titanic was born on its shores

The most famous ship in the world was built in Belfast, at the Harland and Wolff shipyard on the northeast coast. The White Star Line ordered the two largest vessels afloat at the time, the Titanic and her sister Olympic, and spared no expense finishing the Titanic in 1912. She left from Cobh in County Cork on April 11, 1912, at 1:30 in the afternoon, and that was the last the world saw of her on her only voyage. A trip to Belfast is not complete without the Titanic Belfast exhibit, which sits on the very slipway where she was launched.

2. It holds more than fifty islands

Sandbanks and deep channels combine to build over fifty islands in the Irish Sea, a handful of them inhabited. The largest is Anglesey off the coast of Wales, about 260 square miles, home to roughly 70,000 people who reach the mainland across the Menai Suspension Bridge. The most populous is the Isle of Man, with around 83,000 residents. Man is a self-governing British Crown dependency, independent in its day-to-day affairs but overseen from London, and it is known worldwide for the Isle of Man TT motorcycle races and the tailless Manx cat. All of it reads clearly in the underwater topography of an Ireland wood chart, where each island rises out of its own true depth.

3. Its wind farms are quietly powering half a million homes

In 2018 the world's largest offshore wind farm at the time opened in the Irish Sea. It covers an area more than twice the size of Manhattan and generates enough electricity to power over 590,000 homes. Wind matters here because Ireland has almost no fossil fuel of its own, and the supply of wind is anything but scarce. The Atlantic side gets stronger gusts, but the shallower waters of the Irish Sea are far easier to build in, which is exactly the kind of detail a wood chart makes obvious at a glance. The farms have brought jobs and visitors too. The Bord na Mona site in County Offaly added walking and cycling trails that pull locals and tourists into the surrounding pubs and shops.

4. Leatherback turtles pass through every summer

Leatherback turtles turn up regularly in the waters around Ireland and Wales. The largest one ever recorded washed up in North Wales in 1998, measuring nine and a half feet and weighing 2,016 pounds, which is a remarkable size for an animal that lives almost entirely on jellyfish. Leatherbacks spend most of the year out in the open ocean, then drift into the waters off Northern Ireland in the warmer months. If you visit between July and September and keep an eye on the water, you have a real chance of spotting one.

5. It is a playground for water sports

Sailing, swimming, kayaking, and scuba diving are all popular here, and the shallows and drop-offs you can trace on an Ireland cribbage board or wood chart hint at why. Divers can see exactly how deep the water ran around them, and anglers work a coast that gives up mackerel, turbot, plaice, dogfish, and sea bass. With a decent wetsuit you can do most of it year-round, and when the water gets too cold there is always a pint by a pub fire waiting instead.

6. Four major cities line its coast

Because the Irish Sea touches four countries, its shores are crowded with working ports and lively cities. The four biggest are Dublin, Liverpool, Belfast, and Blackpool. Dublin is the largest, capital of Ireland and home to nearly 1.9 million people, Trinity College, and the Guinness Storehouse. Liverpool, across the water in England, gave the world the Beatles and has kept turning out artists, writers, and athletes ever since. Belfast remains a serious shipbuilding port and, of course, the birthplace of the Titanic. Blackpool is a seaside resort that once drew Northern England's factory workers by the trainload and is still the most visited seaside town in the United Kingdom.

7. The second-largest shark in the world lives here

More than thirty-five fish species have been recorded in the Irish Sea, including the basking shark, the second-largest fish on Earth after the whale shark. Do not let the size worry you. Basking sharks feed only on tiny zooplankton and are among the most harmless creatures you could share the water with. They grow up to thirty feet long, and their season runs from April through late July, when they cruise near the surface and can be watched from both boat and shore.

8. Its deepest trench hides a wartime secret

Beaufort's Dyke is a thirty-mile trench running between Northern Ireland and Scotland. It reaches depths of 700 to 1,000 feet and stretches about two miles wide, and that depth is unmistakable on a wood chart. After both world wars, that same depth made it a convenient place to dump surplus munitions: mortars, grenades, rockets, cluster bombs, and anti-aircraft shells all went over the side. The exact tally from the First World War is a mystery, and the lingering ordnance is one reason a tunnel between Northern Ireland and Scotland has never gotten off the drawing board. Undetonated shells still occasionally wash up on nearby beaches, so if you spot a strange metal object half-buried in the sand, admire it and leave it be.

9. You can buy a castle by the sea

Ireland is dotted with castles, from crumbling ruins to immaculate estates, and some of them come up for sale right on the water. Inniscorrig Castle, built around 1847 as a summer retreat for a Dublin physician, sits only thirty miles from the city with panoramic sea views and direct access to the Irish Sea. Five bedrooms, one of them in the tower. It is the sort of detail that quietly rewrites a holiday itinerary to include a stop at the local estate agent.

Bring the water home

A visit to Ireland has a way of outlasting the trip. The best way we know to hold onto it is a wood chart, where every island, channel, and trench in the Irish Sea is carved to its real depth in stacked layers of birch. Explore the Ireland wood chart, or browse the wider range of international charts and find the coast you know best.