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Stay clear of big ships

Stay clear of big ships

Updated 19 November 2014 1:51pm

Wellington Harbour can be a busy area of water. People enjoy the harbour for recreation and sailing but it is also a busy commercial port. These activities usually happen in harmony but occasionally conflict and skirmishes can arise.

This normally happens when small boats get in the way of larger ships. Under bylaw 6.3 of the Navigation and Safety Bylaws, vessels under 500 tons must not impede vessels over 500 tons.

What does this mean? A 500 ton vessel is generally over 50 metres long. The smallest Cook Strait ferry is about 12,000 tons! “Not impede” means not getting in the way of, or not being close enough to, larger ships where the master thinks that you are in the way. Here can be a problem, as what could seem to be a long and adequate distance when viewed from a small boat can appear to be a very small and inadequate distance when viewed from the bridge of a ship.

To put things into a practical perspective, a ship travelling at 20 knots (37 km/h), which is typical for ferries and other large ships, will cover one nautical mile (1.85km) in just three minutes. If the ship has to alter course to avoid a small boat, there are limitations to where it can safely go due to the geographical constraints of the harbour, such as shallow areas. Typically ships can take anywhere up to half a mile (almost 1 km) to come to a complete stop.

A basic form of communication between ships is sound signals. It’s important and useful to know what these signals mean:

  • Five or more short blasts are used to attract another vessel’s attention and means “I am unsure of your intentions”. This should be viewed as a request for the smaller vessel to move well out of the way of the larger vessel, as those on board the larger vessel obviously consider that you are getting too close for safety
  • One short blast – I am turning to starboard 
  • Two short blasts – I am turning to port 
  • Three short blasts – My engines are going astern

When used clear of wharves, this last one usually means that the master is attempting to stop short to avoid running a boat over, and the skipper on the vessel doing “the impeding” is likely to soon receive a visit or communication from the Harbourmaster’s office (and quite probably an infringement notice fine).

So the next time that you are on Wellington Harbour and encounter a large ship or ferry, spare a thought for the master and bridge team, and keep well clear of it. Make your intentions clear by means of early and obvious course alterations, pass well astern of the ship if you are able, and remember the adage “Might is Right”!