The ITF (supported by local unions) may have the power to hold vessels until the wages and conditions are brought up to their requirements, including “back-pay” to which the crew may become entitled. Thus, for vessels flying flags of convenience, Australasia, Scandinavia and Finland are usually excluded. Another stringent union requirement in Australasia and Finland, and in certain parts of Scandinavia, is that dry-cargo vessels must be fitted with hold-ladders conforming to a certain style and dimensions, as defined by the Waterside Workers’ Federation. These require that, for every six-metre drop in the ladder, a resting platform must be constructed. It is not always necessary providing that cargo compartments are completely clean and when loading bulk cargoes that can be “poured” into those compartments, for vessels to have those ladders of that design. However, if there is any problem with cargo holds and the workers are required to descend into the compartments, they will do so only if the ladders conform to the established design. Australasian Waterside Unions are very strong and dictatorial. For ships discharging in Australia, for example, and then reloading, it is almost certain that the unions will insist on cleaning holds after discharge and preparing them for the next cargo – at a considerable cost – far more than would normally be paid to the ship’s crew. Not only that, but the vessel will be delayed in port whilst the work is carried out. This can be another reason why Australasia is frequently an excluded area for ships, no matter what flag they fly. Once again reference to Port Information books is essential to gauge just what is involved in a prospective voyage. Many ports have “hidden” restrictions that one only discovers by appropriate reference. Douala (Cameroon) for example, is what is termed a “neap port”, where tidal levels change dramatically over every week or so, meaning that at certain times a vessel may be prevented from berthing for some days due to insufficient water. Safi (Morocco) has a harbour bar which, at times when Atlantic Ocean roller waves are predominant, means extreme difficulty for ships of certain drafts in entering the port. Particular berths in Genoa (Italy) have an air-draft restriction – not a physical restriction, but one nonetheless rigorously imposed by the port authorities because of the danger to aircraft overflying the port area to and from Genoa airport.