His FishWorks chain hit the rocks, but Mitch Tonks is back with a small-fry operation that's making a big splash

"Six knots, no wash." The harbour-front sign may be directed at the river traffic, but it goes for everyone around here. Dartmouth is pure tootling territory. Or should that be pootling – I never can remember which is slower. Let's just say it's a place to mess about in boats, cast a line, sink a pint, tuck into a Devonshire tea, or just take a little nap under the oak trees.

Recently, it has also become something of a retreat for frazzled restaurateurs; most notably John Burton Race, a former Michelin star-chasing, high-octane chef drawn there, he says, because he fell in love with the hedgerows, quiet lanes and deserted sandy beaches.

Now, just two doors away from Burton Race's New Angel, FishWorks founder Mitch Tonks (right in picture) has opened The Seahorse. Tonks' life has been more of a hurtle than a tootle since his first little seafood café in Bath grew into a fully fledged chain of fish shops/bistros with a rapid expansion programme. Too rapid. Shares dropped, new management stepped in, and Tonks put up a "Gone fishing" sign. Hurtling too fast isn't good for anyone.

So he tootled off to Dartmouth and set up The Seahorse with chef Mat Prowse (left in picture) and musician mate Mark Ely instead. It is not at all what I thought it would be. Instead of a happy-go-lucky seaside caff, it feels more like The Ivy by the Sea. The 40-seat interior borders on the sumptuous with its studded mustard leather banquettes, pressed white tablecloths, monogrammed plates and library-shelf wall of wine. Through a large window, Prowse is doing a fine impression of a whirling dervish over his pots and pans and the kitchen's pride and joy, the smart new Spanish Josper charcoal grill/oven.

The menu is a slow tootle around the Med, stretching from clams with ham, Manzanilla sherry and jamon, to a fritto misto of local fish, with local lamb and south Devon beef also getting a look in.

It is very quickly obvious that The Seahorse is all about the produce. Local Dartmouth crab (£11) is racistly grouped in clumps of sea-bright white and creamy brown meat, with a goodly dollop of mayo and a few salad leaves; perfect stuff. The sage-infused char-grilled chicken livers (£7.90) are bloody and marvellous – crisp on the outside with a smoky, scorchy richness. These alone would be enough to justify the purchase of the Josper.

With the three partners and their wives all hands-on, the service has a quirky charm. So does the music: in among the Beth Orton and Damien Rice, Ely slips in a track or two of his own work. So, too, does the wine list, an inviting selection full of little-known but highly regarded Italians. Barbera d'Asti can be an annoying wine, often vacuous and one-dimensional, but my Braida Montebruna 2005 (£38) is all silk and smoky plums.

The world slows to a stop when my earthy, stewy Menorcan lobster caldereta (£29) arrives in its glazed terracotta bowl. I would not normally order lobster but a) this is local, b) this is lobster season and c) are you kidding me? Lobster can cost up to £40, I can't not order it. It's an absolute treat, the big chunks of lobster meat so lightly cooked the flesh remains supple and succulent; the stew rich, oily and unctuous.

Other dishes don't ride the same wave. Char-grilled squid with a rich squish of sweet red-pepper peperonata (£16) is too much of a single thing. Potato chips are softish, and a finale of goat's cheese with rosemary honey and a glass of Sancerre (£10) isn't quite the match it should be.

The Seahorse is extremely likeable, for its sense of place and for showcasing the produce of land and sea with such single-minded style. I'll certainly be tootling back as soon as I can. Tonks himself is, of course, away filming for television and planning a new restaurant in Brixham. Some people just can't tootle to save their lives.

15/20

Scores: 1-9 stay home and cook, 10-11 needs help, 12 ok, 13 pleasant enough, 14 good, 15 very good, 16 capable of greatness, 17 special, can't wait to go back, 18 highly honourable, 19 unique and memorable, 20 as good as it gets

The Seahorse, 5 South Embankment, Dartmouth, Devon, tel: 01803 835147. Lunch, Thurs-Sun (August: Wed-Sun); Dinner, Wed-Sat (August: Tues-Sat ). Around £115 for two, including wine and service

The crunch bunch: Fine fish for less

The Dolphin Inn

12 Rock-a-Nore Road, Hastings, East Sussex, tel: 01424 431 197

As reviewed here recently, this popular Hastings boozer serves up a two-course lunch featuring fish straight off the boats that morning for just £6. Beat that

The Fish Club

189 St John's Hill, London SW11, tel: 020 7978 7115

A sophisticated bistro in which everything from a prawn cocktail to classic fish and chips is available to eat in or take home. Dinner for two with wine is about £45

The Seafood Restaurant

The Scores, Bruce Embankment, St Andrews, Fife, tel: 01334 479 475

This eye-catching restaurant housed in a sleek glass box perched above rockpools is known for consistently good seafood. Lunch is good value: £22 for two courses