Model shipbuilding: an ancient craft

''Little data remain regarding precise appearances and dimensions of antique ships - the Vikings', pharaohs', and even our early naval vessels,'' says James S. Wiser, a model ship builder.

This is the reverse of historic restoration and preservation of homes, for which books, blueprints, and other documents record the exact patterns and designs of early log cabins, saltboxes, and Federal, Georgian, and Victorian structures. Houses, churches, restaurants, barns, and theaters have been restored to their original appearances, or reproduced to appear like the old.

Sitting in his Southport living room, Mr. Wiser says, ''These early ships represent man's effort to build vessels that could weather all sorts of storms'' and conquer new lands.

The victor in creating a number of models (including his 35-inch-long replica of the 19th-century US frigate, President, sister ship to the USS Constitution), Mr. Wiser is also an avid student of early ships. In his own construction activities, which take place in a second-floor room of his home called the ''shipyard,'' Mr. Wiser consults magazines, books, copies of plans from museums, and many other resources he gathers from around the world.

The walls are decorated with photographs, paintings, and prints of seafaring vessels, naval-related items (including scrimshaw carvings), and a number of his own models, which are displayed in glass cases. In addition to this wealth of information, the ''shipyard'' is filled with tools, among them pieces of wood, glue, tweezers, drills, wires, scissors, clay, and chalk.

The craft of building ship models is ancient. ''You have to have plans in order to build a structure - ships are no different,'' he says. ''Models were built as far back as King Tut, and even earlier.''

A large portion of Mr. Wiser's work takes place under a magnifying glass (his President is on a scale of 1/8-inch to 1 foot). Because he is meticulous about details, it has taken about three years to complete a model. His work represents the exact construction of the original ships - for example, plank-on-frame construction.

Included in the fleet of ships Jim Wiser has re-created are:

* Flying Cloud, an 1851 Boston ship used in the East Indies trade. This model was begun by his father in 1920 and completed by Mr. Wiser after World War II. It was his first model.

* Nokomes, a 60-foot schooner he and his father sailed on Long Island Sound during the '30s.

* Two 19th-century warships: HMS Victory and the President.

* An Egyptian hog truss punt from 1400 BC.

Model-builder Wiser also restores antique models. He has recently completed work on a bone model from the late 18th or early 19th century. His ''shipyard'' is jammed with blueprints, plans, and materials for his immediate work: a model of the Echo, a 200-year-old British sloop-of-war. ''I sent for plans from England,'' he says. ''There wasn't too much available, and I've had to do a lot of research, and use some imagination.''

The Echo will be open on one side, like a dollhouse, and fully furnished below deck, including lanterns. It will present a vivid picture of what this ship (and others of the same period) looked like.

Ships reflect the trends of the times, society, and political activity, and change ''according to economies, capacity, weathering, and sailing abilities,'' Mr. Wiser notes. ''Everything has progressed for specific functions. Ships have slimmed down and narrowed for purposes of speed and design.''

Mr. Wiser's wife, Norma, their two daughters, and three grandchildren share his enthusiasm for shipbuilding. Over the years Mrs. Wiser has picked up books and other materials on sea vessels from her work at bookshops and libraries.

The hobby takes a great deal of time, Mrs. Wiser says, adding, ''Sometimes he's in the 'shipyard' for eight hours.'' He admits he can get absorbed in the work, but he can put it behind him just as easily for a game of racquetball, or other activities.

There is a market for ship models - on fireplace mantels, in collections of nautical antiques, and in museums. Mr. Wiser has sold several of his models. There are also groups for model ship builders. He was president of the Connecticut Marine Model Society for a number of years.

What is required to be a model-builder? ''An interest in and love of the sea and things nautical, a steady hand, a knowledge of ships and of marine construction,'' he says.

Mr. Wiser's hobby gives him challenges, considerable pleasure, and a finished product that offers others a close-up view of history - of ships, what they looked like, and preservation of an important part of mankind's past.