A short-drag or short-haul chantey. The usual method of singing this is to begin the verse as the previous refrain ends so that the words "haul" overlap. The verses are improvised. These are sample verses. This may be one of the oldest chanties around: the bowline is a knot and also the line used to pull the weather edge of a square sail as far out to windward as possible when reaching as close to the wind as possible, the vessel being said to be “sailing on a bowline” once this is achieved. It was made somewhat obsolete by the introduction of staysails in the early eighteenth century. Recorded by Ewan MacColl and A. L. Lloyd, The Young Tradition, Steeleye Span, the Clancys and many others. I don't remember where or from whom I learned this.