Imagine a voyage like this... sailing out of Cape Town with Table Mountainand the great continent of Africa behind you, it takes a few days to get away from the influence of coastal currents before picking up the ocean breeze that will take you to the lonely island of Saint Helena, caught in a time warp. As you voyage you will be accompanied by sea birds and schools of dolphins that come to investigate the boat, and maybe the sighting of a whale. Then you have the chance of heading for the laid-back Caribbean or sailing into the spectacular Bay of Guanabara, where Rio de Janeiro and a whole new continent and culture to is waiting to be explored.

If the demands, pleasures, and challenges of ocean voyaging are your dream, it's easy enough to make your dream come true.

If you are considering the possibilities of sailing on a private yacht as a crew member, the best way to proceed is by registering your name for a small fee with organisations such as the Cruising Association (tel 020 7537 2828, website www. cruising.org.uk) or Crewseekers (tel 01489 578319, website www.crewseekers.co.uk). They hold lists of members or contributors requiring crew. Consult the personal advertisements in yachting magazines such as Yachting or Yachting World. Check out your local yacht club - ask the secretary what the procedure is. If you place an advertisement of your own, it should include the following information: name, nationality, sex, age, crewing experience, skills, date available and proposed duration of trip, desired destination, financial arrangements (contributory basis/ proposed payment) and a place/address where you can be contacted. It helps if you date the advertisement and add a photo.

It is very important to meet the skipper and see their yacht, as you will need to make assessments about their ability and the vessel's seaworthiness. Does it have the necessary equipment on board for all weather conditions: sails, navigation lights, navigation sextant and satellite, communications, life-raft, emergency tracking system and dinghy? Is the galley properly set up, are the heads adequate, what are the sleeping arrangements? Are the vessel's documents and the skipper's sailing certificates in order?

In return, they will want to know about your skills. You will be expected to have basic sailing skills at least, but more important than being an expert sailor is a willingness to do anything that may be required. Desirable skills include cooking, computer literacy, an aptitude for diesel mechanics, diving, electronics expertise, an inventive engineering ability, languages, medical knowledge, musical talent, navigation, sewing, experience as a teacher or nanny, and radio/communications experience. You will need to be organised to carry out your duties; for instance, if you've signed on as a cook, do you have recipes and adequate equipment on board? Mechanics should brush up on marine engines, check that manuals and tools are on board. If that's going to be your responsibility, you may want to take overalls. For sewing, do you have sail- repairing needles, 'palms' and other material on board?

Your own gear must be kept to a minimum and packed in a foldaway synthetic holdall. Keep your clothes in plastic bags. Your equipment should include: foul-weather gear, scarf, life-vest, safety harness, deck shoes, gloves, peaked hat, sun screen, sea-sickness remedy, personal medication, sunglasses and spare prescription glasses or lenses.

Keeping in touch needs to be organised. Before you leave, make sure that there is one person at home with whom you can co-ordinate your activities - that way you don't have several people to advise of your schedule. Your nominee can also collect your correspondence and forward it on to you. Make sure people understand that timings will be extremely flexible to save them anxiety when you don't call from, say, Cape Town, on a predetermined date.

Make sure people only use your surname with initials on correspondence, then it won't be accidentally filed under your christian name at your poste restante. International telephone calls are often a major exercise in those areas with limited facilities and major time differences. Email has made life easier, so you could consider using a service such as info@nautimail.com, website www.nautimail.com.

Skippers will ask you to contribute to general running costs, including food, mooring and immigration fees. The rate varies according to the situation, but it is usually around US20-25 a day. It is not usual to contribute financially to yacht maintenance, although your elbow grease will be required. Apart from the 'onboard' living costs you agree, you will have to have a return ticket/MCO or the equivalent amount in travellers' cheques. Be prepared to 'bond' these with the skipper as he will be responsible to immigration and port authorities for crew members' repatriation. Keep all your documents in sealed plastic bags: passport, inoculation certificates, letters of reference, skill certificates, cash, cheques, tickets and insurance documents.

If you are looking for a paid job as skipper, deckhand or cook you will need references from previous skippers and certificates of competence. Information about certificates for all levels of competence is available from the Royal Yachting Association (tel 02380 627400, website www.rya.org.uk). Wages are minimal as living is 'all found' on board. Work is usually seasonal with charter and flotilla holiday companies or yacht deliveries. There are training establishments for skills associated with marine leisure activities and agencies which specialise in marine placement. Try the Hamble School of Yachting & Professional Training (tel 02380 452668, email tuition@hamble.co.uk) or Leisure Management International (tel 01983 280641, email mail@lmitraining.com). Consult the small ads in the yachting magazines.

Having agreed on finances, duties, and intended destination, the last but most important factor of all is compatibility. In the end it does not matter whether the vessel is state of the art or just adequate or the weather is foul or fair, if you do not get on well together the voyage could be disastrous. This is the hardest thing to get right, since there is no real way of knowing before you are on the high seas. A weekend 'shake-down' cruise is recommended to give everyone the chance to assess each other and the situation, but you could still be in for some surprises if you are considering a long voyage - even if you are sailing with someone you already know well! Personality problems are greatly emphasised in the limited environment of a yacht at sea, the boat has a greater chance of surviving than the crew, and the skipper has the last word on everything, so you must be prepared to obey - like it or lump it!

There are pros and cons for leaving from your country of origin. Skippers usually have family and friends to sail with at the beginning of their voyage, so finding a place can be harder even if you are on home ground. It is when these friends have to return home that the skipper will need to find crew en route, and at certain seasonal bottlenecks itinerant crew can be much in demand. Some of the major ones include the Solent in May, Las Palmas and Saint Thomas in November, Grenada and Durban in December, Cape Town in January and Tahiti in April and September. So sometimes it is worth flying out to the area you wish to sail in and putting up a notice in the local yacht club, meeting place, poste restante or launderette. Groups of yachts travelling together often operate a 'net' on ham radio or VHF, where crew requirements can be announced. These opportunities for finding a crew position come easier with experience. If you are sailing from the UK, the beginning of May to the end of August is the optimum time; in the Mediterranean it is between the end of March and the end of September. The Caribbean season runs from the end of November until March, but if you are sailing from Europe you should be leaving to cross the Atlantic between the end of September and early November. The Pacific season is from April to September, so yachts should be transiting the Panama Canal during March. The season for the Indian Ocean, via the southerly islands, is July to October. The growing popularity of rallies provides added opportunities to crew for yachts that enter them, find out when the major ones take place from the Cruising Association, details as before or the World Cruising Club (tel 01983 296060, website www.worldcruising.com).

You should remember that sailing is an archaic form of transport. When you travel by yacht you are reliant on the elements to get you from A to B, not a timetable. You play a major role in achieving this, living by a 24-hour watch, sleeping, cooking, eating, cleaning, sail changing and taking the helm to fit in with that routine. Life at sea has to be learnt: the motion of the boat and sea conditions must be accommodated while you fulfil all your roles. Your normal routine: sleeping, washing, eating, all must to be adapted to life on board ship.

The golden rule is: one hand for you, one for the boat. Everything has to have its place, and must be returned there after use and be stowed away properly. Doors, hatches, portholes, cupboards and drawers all have safety latches that must be used or the vessel will become unsafe and unmanageable. You cannot have an untidy boat at sea. The practice of conserving (in as much as it is possible) fresh water (usually for drinking purposes only), fuel, battery power and light is extremely important. You must learn how to use all the pumps properly, from the galley to the bilges - and particularly the heads - if you don't you could sink the vessel.

Life at sea is completely different to life on land. You are always exposed to the elements: sun, wind, rain squalls, and you are absolutely reliant on yourself and your crew mates on the high seas. There will be great challenges and periods of calm, there will be both companionship and solitude, and, above all, there will be the freedom of the oceans and the excitement of landfall and new places to see.