The menu is mercifully free of generic boat curry: there are seven varieties of curry, plus a good range of stir-fries, salads, and an interesting fish section.

It's difficult to get someone to take food seriously when they are bobbing about on the water. You get on a boat to sail; to enjoy the view; to travel from one point to another. Any eating is strictly incidental to proceedings, and digestion is not improved by either the movement or memories of your mother's dire warnings about swimming on a full stomach.

If you want to get an idea that food and boats are not natural partners, put “food on a boat” into Google. The first two results will bring you recipes for “generic boat curry” and “generic boat stew”, followed by “tugboat turnips”, which, for the curious, involves mashing turnips with carrots, butter and sugar.

All of which means that floating restaurants are a curious beast. Their very location is a gimmick, and it is difficult to escape the suspicion that the proprietors are trading on the view or the novelty value rather than the food.

Which of these has been capturing the attention of Norwich residents since Thai on the River opened late last year is hard to say. On Riverside in what used to be the floating Chinese restaurant, from the road it is hard to tell that anything has changed.The menu is mercifully free of generic boat curry: there are seven varieties of curry, plus a good range of stir-fries, salads, and an interesting fish section. The dishes are listed in Thai, which means that easily-amused English people like us can laugh at some of the names, Plaa Lard Prik (fried fish with Thai basil, onion and chilli) being my particular favourite.

The prices are not noticeably taking advantage of the location: curries range from £6 to £14 for sea bass, set menus are £16 upwards, and rice is around £2.

Inside is bigger than you would think, with décor that will please wood fans, while the downstairs tables are almost at eye level with the waterline.

We spent about 20 minutes picking various combinations of starter, main course, rice or noodles before spotting the set menus at the back.

We settled for something called a green feast, only for the waitress to return a few minutes later and check we knew it was a vegetarian menu. I had rather thought the clue was in the name, not to mention in the meatless dishes listed.

We wondered whether we were the first people who had ever ordered it, or if there had been a previous incident involving tantrums from a disappointed carnivore.

Notwithstanding this, our starters appeared in the blink of an eye, four dinky spring rolls filled with clear noodles and shredded vegetables, and four deep-fried sweetcorn cakes of a slightly curious texture and not unpleasant flavour. There was sweet chilli sauce for the latter, and what might have been plum sauce for the former.

We moved swiftly on (for a boat that doesn't go anywhere, everything about this place is very swift) to main courses.

The star was the red curry, nicely spicy with chilli, lime leaves and coriander leaves, rich with coconut milk, and with a nice range of vegetables, including peppers, bamboo shoots and Thai pea aubergines, which are nothing like peas and not particularly like any aubergine you might recognise. The flavourings were spot on, and it was as good a Thai dish as I have had anywhere.

Then there was the stir-fried tofu, an ingredient with which I have long had difficulties.

As far as I can see, it tastes of nothing, and it has a texture ranging from crème brulee to bathroom sponge. The combination leaves precious little reason to eat it. Over the years I have had reluctantly to admit that in the right hands it can be made to resemble something that you might at least eat if you were desperate.

Thai on the River had managed to deal with the flavour issue quite well. The bean curd had absorbed the sweet and sour sauce to the point where it tasted of something, and was stir fried with enough peppers, onions and pineapple to add interest.

There was still the small matter of the texture (this one was towards the sponge end of the scale), but as tofu goes it was not too bad.

Stir-fried rice noodles with egg, soy sauce and bamboo shoots also contained a rogue chunk or two of tofu, but was generally quite pleasing.

There was a generous amount of steamed jasmine rice, though the Real Ale Drinker maintained that the other portions could have been bigger, while I had eaten more than enough by this point.

By the time we had drunk our coffee and green tea, we had almost forgotten we were on a floating restaurant. And that, in my view, is as high a recommendation as can be said for it.

t Thai on the Riverside, Norwich; 01603 767800; www.thaiontheriver.com

t Where is it? Across the road from the main entrance of Norwich's rail station.

t Is there parking? No, the Riverside multi-storey is probably your best bet.

t Do I need to book? Only at busy times or if you are in a large group.

t Can I smoke? The downstairs restaurant is non-smoking; you can smoke upstairs.

t Disabled access? It is on a boat and not ideal for those with mobility problems - there are quite a few steps.

t Is it a chain? There is a Thai on the River in Battersea, London, so this is their second outpost.

t What about vegetarians? As well as the vegetarian set menu (minimum two people), there is a reasonable selection of vegetable curries and stir-fries, though spring rolls and mushroom soup are your lot as far as starters go. Strict vegetarians might want to watch out for fish sauce and oyster sauce.