Two nights at sea, as a trial run, from Portsmouth

There are people who love cruising from the first evening, and there are people who discover, somewhere off the Lizard with the soup going sideways, that they would rather be almost anywhere else. Nobody can tell you in advance which you are. The only way to find out is to go to sea, and the least expensive way to go to sea is for two nights, from one British port to another, with a train ticket home.

This is what the short one-way sailings are for. Ships reposition around the coast between longer voyages, from Portsmouth to Liverpool, say, or from Portsmouth up the east coast to the Tyne, and rather than sail empty they sell the passage. What you get is the whole of cruising in miniature: the boarding, the cabin, the dinner, the first night's sleep with an engine somewhere beneath you, a day at sea and an arrival. What you do not get is a large bill, or a fortnight's commitment to something you may not enjoy.

The questions a short sailing answers

The things that make or break a cruise for most people are not the ones in the brochure. They are more domestic. Do you sleep well with a gentle, continuous hum and the occasional creak? Do you mind the sea when it has a bit of swell on it? Do you like dining at a set time with the same people, or does that make you want to hide in the cabin with a sandwich? Is a day with nothing to do but watch the coast go by restful, or does it make you restless by eleven in the morning?

Two nights will not answer all of these perfectly, but it answers most of them. It will also tell you practical things: whether an inside cabin feels snug or airless, how much you would actually use the balcony you are thinking of paying for next time, and whether you prefer the busy lounges or the quiet corner of the deck. People who come back from a taster sailing tend to book the next cruise with much more confidence, and a better idea of which cabin to choose.

It is worth remembering, too, that this used to be an ordinary way to get about. Before the railways, and for a long while after them, coastal steamers carried passengers between British ports as a matter of routine, and a paddle steamer from London to Margate was a standard day out for Victorian Londoners. The two-night passage from Portsmouth is, in its way, a revival.

Portsmouth, and which way to turn

Portsmouth is a good place to start anything nautical. The historic dockyard holds HMS Victory, Nelson's flagship at Trafalgar, and what survives of the Mary Rose, Henry VIII's warship, which sank in the Solent in 1545 and was raised in 1982. If you arrive early by train, the harbour station is a short walk from the dockyard gates, and a morning there is a better preparation for a sea voyage than the departure lounge.

From Portsmouth the ship turns one of two ways. West, it runs down the Channel past Dorset and Devon, rounds Land's End and the Cornish coast and heads up the Irish Sea to arrive in the Mersey, with the Liver Building and the rest of Liverpool's waterfront lined up along the river to greet it. It is one of the great arrivals by water in Britain, and it was the last view of home for millions of emigrants who left from here for America in the nineteenth century.

East, it runs up the Channel, through the Strait of Dover with the white cliffs off to port, and then up the North Sea coast of England to the mouth of the Tyne. This is a busier stretch of water, and a more industrial one, and on a clear day it is fascinating: the shipping lanes of the Strait are among the busiest in the world, and you can watch the traffic from the deck like a slow-moving motorway.

A little of France, and a little of the nineties

Not every taster keeps to British waters. One sailing leaves London Tilbury and calls at Honfleur, the old harbour town at the mouth of the Seine, before finishing in Portsmouth. Honfleur is small, very old and entirely on the water: its inner harbour is lined with tall, narrow houses, and the Impressionists painted it so often that it can feel faintly familiar even on a first visit. It is also a good test of a different kind, because a day ashore in a foreign port is the real business of most cruises, and it is worth finding out how you like going ashore and coming back to the ship.

Other short sailings come with a theme attached. A two-night run from Tilbury to Portsmouth is billed as a tribute to the nineties, which gives you a fair idea of the evening entertainment. There is no harm in this, and some people like a party as their introduction to the sea, but if what you want is to lean on a rail and watch the Sussex coast go by, pick a sailing without one.

What to take, and what to expect

Take less than you think. On a two-night sailing you need one smart outfit for the evening, layers for the deck (it is always colder at sea than on land, even in May), comfortable flat shoes and something to read. Seasickness remedies are worth packing in case: the Channel and the Irish Sea can both be lively, and April and May are not always calm.

Check the return journey before you book. One-way sailings end a long way from where they started, and the train from Liverpool or Newcastle back to the south coast is a proper journey, so it makes sense to book it early and consider a night in the arrival city rather than rushing off the ship to catch it. Liverpool and Newcastle are both worth a night.

The principal thing to expect is that you will know, by the second morning, whether you want to do this again. If the answer is yes, the next question is where. That is a longer and much more pleasant conversation.