Abstract: A portable base is provided for supporting an upstanding mast and particularly a davit with a jib where the jib includes a load connecting point arranged such that on application of a load beyond a predetermined limit the spacing of the load connecting point from the mast is reduced to reduce a side load on the base. The base includes bottom and side panels connected edge to edge to form a container with a hollow interior filled by concrete where at least one side by side panels forming a top wall has a sleeve extends from the panel at least partly through the hollow interior to the base. The sleeve which is welded to reinforcing bars passing through the material receives and supports the mast and is held in place by forces contributed both by the set filling material and the panels.