Facts You Should Know

From a recreational vessel skipper’s perspective, getting into a close quarters situation with a large ship can be quite unnerving. The one major fact that needs to be faced up to is that a confrontation with any massive, swiftly moving vessel literally thousands of times your size, will result in a contest you won’t win.

Other facts you need to consider include:

The number of recreational boats in the Port of Fremantle waters has increased over time, multiplying the chances for collision with large ships. Unlike many small boats, these ships must keep to an often narrow channel or pre determined approach and departure course.

In the Port of Fremantle, all foreign-flag commercial ships you encounter will have a Fremantle Pilot aboard. The Pilot will be monitoring VHF radio channels 16 and 12.

The PILOT BOAT DOES NOT GUIDE SHIPS to and from the port. It’s task is to transfer Pilots to and from ships. Some make the mistake of thinking it guides a ship and therefore think that by keeping and eye out for the Pilot Boat, that this will somehow give them an indication of approaching shipping.

Ships are the largest moveable manmade objects on the planet. Ship’s weighing more than 160 000 tonnes and up to 350m in length (more than three football fields!), have beams of over 40m and drafts (submerged section of the ship) up to 14m. They can move at 20 knots or more in the open ocean. However their manoeuvrability, stopping distance, turning radius, and visibility are severely restricted by their size, and by the channels in which they operate. With these limitations, Pilots must carefully consider each manoeuvre in terms of the waterway and other boat traffic well ahead. Plans to slow and stop are literally made by the Pilot miles in advance.

In general, most large ships travel at a “manoeuvring speed” of between 8 to 15 knots while in the Cockburn Sound and Gage Roads, but in open waters they may be going faster.

Ships often travel faster than you might expect given their size, and they must maintain adequate speed to maintain steerage and manoeuvrability.

Lightly loaded vessels must keep a good speed to stay under control when in channels. The same is true of loaded vessels that are unevenly trimmed. If they slow down too much or stop, they risk being driven aground by wind, current or tide.

It often takes less than 10 minutes for a fast ship to reach you once you spot it in clear weather, and in hazy weather it takes a lot less. At 10 knots, a ship goes 1 nautical mile in 6 minutes; at 15 knots from a mile away, it can be on you in 4 minutes. DO NOT HESITATE, MOVE CLEAR AS SOON AS YOU SEE THE SHIP.


Large, difficult to manoeuvre ships cannot successfully avoid smaller craft in narrow channels, or approaches to these channels. IT IS UP TO YOU TO STAY CLEAR.

Be aware that in Gage Roads and Cockburn Sound, the shipping lane is not always clearly defined, especially in long open stretches. Refer to  Shipping Lanes & Channels

A ship will slow down as it enters the Inner Harbour or approaches a berth, and as it slows it does not steer as well, the rudder needs a flow of water against it’s surface to remain responsive.

If the Pilot is required to stop the vessel as quickly as possible to avoid danger, the ship’s engines are put “full astern,” there is not much more the Pilot can do, and the vessel may lose steerage. In many cases this action will swing the ship’s bow to starboard, but precisely how a ship will react when it’s engines go astern will vary. Therefore, STAY WELL AWAY. Remember, depending on draft and load it make take a ship a mile or more to stop, after it’s engines are put astern.

Big ships are also restricted in their manoeuvrability by water depth. A ship’s ability to manoeuvre, and the distance required to turn are functions of speed. The effects of shallow water dramatically affect turning diameter,  (the distance required to turn the ship), and this can double in shallow water. The ability to steer the ship depends on the force of water being pushed against the rudder. The faster the ship moves, the more manoeuvrable it is. As the ship approaches a berth, the Pilot will take the decision to stop engines and reduce the vessel speed, This in turn dramatically reduces the vessel’s steering ability to a point where ultimately the ship is effectively drifting.

Visibility is a major issue on big ships. On a 300m container ship, the bridge is usually about 30m above the water. However the line of sight is further restricted by the rows of containers stacked forward of the bridge. It is typical to lose sight of a powerboat or yacht some 500m ahead, and in some circumstances up to 700m.  The recreational boat skipper’s perception of the distance between his boat and potential danger is completely different to the Pilot’s perspective. Looking up from the water level a half-mile away, the skipper can clearly see the ship’s bridge and wrongly assumes the Pilot can see him and that he has plenty of room.

In low visibility, ships navigate by radar, and small craft may or may not be detected. DO NOT ASSUME THE PILOT HAS SEEN YOU.

Other smaller vessels that operate throughout Port of Fremantle waters must also be avoided. Watch out for tugs towing barges, especially at night when poorly lit barges may remain invisible. Remember that a partially submerged towing cable can cut a boat in two.

Even though commercial Pilots are on a larger vessel and as such run a much lower risk of personal injury than pleasure boaters, this does not mean that they find encounters with small boats any less nerve wracking. Pilots are programmed to protect all that they responsible for, i.e. vessel, environment, port and community infrastructure. That includes you and your recreational vessel, and all on board, The Pilot will do everything within their power to avoid collisions and near misses. Ultimately their professional licenses and thus livelihoods are at stake, and they risk lawsuits, liability claims, and even criminal prosecution and potential jail time, not to mention the guilt of having been involved in potential injury or death with every passage. They balance this with the demands of commercial pressure of moving vessels to and from port on a very tight schedule, at all hours and in all weathers.

With all of these limitations to factor into a constantly changing and complex traffic equation, Pilots of big ships can use all the help they can get, especially in narrow channels and the Inner Harbour with heavy boat traffic.

You can avoid “close encounters of the dangerous kind” by following the COLLISION AVOIDANCE practices in the following section whenever you are operating in and around big ships.