In the most general sense, a liveaboard refers to the practice of living aboard a boat. The term "liveaboard" may be taken to mean either a person who lives on a boat, or a boat designed for people to live aboard it.
There are many different kinds of liveaboards, each offering very distinct experiences. Liveaboards encompass all kinds of watercraft, as well as a diverse group of people. A liveaboard may constitute a sailboat with only 3 or 4 hands on deck, motorboats, houseboats equipped with complete modern amenities, trawlers, yachts with full crews, sailors, retirees, divers, and more. The liveaboard lifestyle has been in evidence since time immemorial and continues to have many followers today. In fact, there are many publications, businesses, and personnel that cater specifically to the liveaboard way of life.
In overseas tourism markets, however, liveaboards generally point to recreational diving boats. These boats will usually advertise certain out-of-the-way dive spots which can only be accessed by committing time to open water travel. More established liveaboard programs will include the opportunity to stay on board for a set number of nights, a certain number of dives per day, meals, as well as some form of evening recreation. For avid divers, the ability to travel to more distant diversities is a privilege worth all the downsides of living in close confines on the open sea.
For people considering spending time on a liveaboard, it is important to note that while modern boats may come equipped with various comforts and luxuries, you will still be living within relatively confined spaces, will be cut off from land, and may find yourself in strange situations or a victim of any number of exotic diseases. It is both wise and prudent to make sure that there are enough life jackets for all the passengers and crew, first aid kits, various important medicines (headaches, fevers, etc.), and an ample supply of water are all readily available. It is also important to make sure there are means by which you may communicate with the outside world while onboard. Certify that the captain is well-qualified, and if you are on a liveaboard dive program, make sure that the boat (and its crew) has the ability to address diver-specific problems, such as decompression illness, stings and bites of poisonous marine life, equipment failure, etc.