An in-depth study of the principal recorded dugout boat, or logboat, discoveries made in the northeastern counties of Northern Ireland since the latter half of the 19th century. In this region fresh examples continue to turn up at a rate of about two a year in rivers, lakes and also around the coast. Northern Ireland has also been the scene of two significant series of experiments with logboats, in 1959 and again in 1994-95. These were undertaken with the objective of throwing light upon the performance of ancient hulls, particularly as regards safe loading, for which a formula for rough calculation purposes is presented. A detailed inventory, which tries to compare as well as describe, owes much to the fieldwork and research of the late Bill Seaby, former Director of the Ulster Museum, whose labours over 20 years have been amalgamated with records kept over a similar period by the present author. Included in the account are 120 craft of all shapes and sizes, no less than 48 of which have been dated. The chronology thus established extends over 7000 years, from the 55th century BC to the 17th century AD.