Last Sunday afternoon the weather was glorious and the West Pier at Howth was thronged with people – the market was busy, the restaurants were hopping and the fish shop was doing a roaring trade in fish scraps at €2 a bag (gloves included) for the extremely well-fed seals that live the life of Reilly hanging out in the water alongside.

My editor has been telling me for months to visit the Oar House, which occupies a converted coal shed on the Pier within an easy stroll of the station. I finally ran out of excuses and now that I've been it'll become a regular destination. We had thought to saunter out and try our luck but thankfully made the call and were told that we would definitely need to book. The apologetic person on the end of the phone advised that we would need to give a 2pm table back at 3.40pm, which happened to suit us fine on this occasion. All afternoon prospective punters were being turned away, their faces disconsolate as they glanced around the room and saw what they were missing. The next time, I fancy we'll take the Dart and linger awhile.

The interior is nothing to write home about – lots of stained pine and fishing nets interspersed with seashells and various nautical bits and bobs. Our lovely waitress looks almost smug when she tells us that one of the owners of The Oar House (the others are the head chef and John Aungier of the Casa Pasta restaurants) is John Doran, who owns the fish shop next door – the one for which those seals should be down on their knees (if they had them) thanking God every day. Not just the seals, judging from the queue of people (plenty of blue-ginghamed chefs' legs from the pier's other restaurants amongst them) which snakes in and out of the shop all afternoon. Dublin Bay Prawns seem like a bargain at €10 a kilo and the fish looks spankingly fresh. "It is," she says, grinning, "the reason why our fish is so good".

There's a printed menu and daily blackboard specials. There are a few veggie, meat and chicken options for non-fish eaters, although to order them would be to miss the point of the Oar House. We start with Whole Soft Shell Crab Tempura with Mustard and Basil Mayonnaise (€6.95), Dublin Bay Prawn Cocktail (€10.95) and a large portion of the Calamari (€15.95). The crab has been on the menu for only a few weeks, lovely waitress tells us, and not many people are ordering them – "I think they're afraid of them," she says. More fool them, we say, chomping through their delicious, light batter. The prawn cocktail was classic: perfect prawns with Marie-Rose sauce atop shredded iceberg, and the calamari was terrific, coated in more good (though different) batter, heaped up on the plate and served with two dips – a sweet chilli relish and a home-made tartare.

We ordered two mains and an extra side order of chips (€3.50) between the three of us. The Grilled Hake with Prawn Sauce (€23) was the least showy of the dishes that we ordered, but nonetheless good for that. It came with a small multi-coloured salad that looked garish but tasted mighty fine. Fish and Chips (€15.95), a huge portion of haddock on the day that we were there (it changes on a daily basis), served with mushy peas, came in yet another excellent batter – beer this time. The chips passed the Ellie (9) test with flying colours. After all that, we said 'no' to pudding – the offering included stalwarts such as Mississippi Mud Pie, Banoffi and Apple and Rhubarb Crumble, which neighbouring customers were demolishing happily.

With a carafe (€10.95) and an extra glass (€4.95) of a decent (that is to say, decidedly more-ish) sauvignon blanc, one soft drink and plenty of free tap water our bill came to €104.72 including 10% service. We added an extra €10 for the charm of it all.

So, for being the type of restaurant that you'd be more than happy to find in any seaside town in the world (just a shame that there are so few like it in Ireland) the Oar House gets five stars, for doing what it says on the tin – and doing it impeccably. Monday to Friday you can eat two courses for €22 and three for €25 between 3pm and 6.45pm. Never mind early bird (or early fish as they call it at The Oar House), that sounds like a perfect late lunch on a summer afternoon to me.

The Oar House, 8 West Pier, Howth, Co Dublin. 01-839 4568. Rating: 5/5