About PPUs
Portable piloting units give pilots their own source of extremely accurate heading
and positioning data.
They use special piloting software, overlaid on official electronic charts. The positions
of surrounding ships can also be shown.
A PPU is an important tool in:
- Avoiding accidents or incidents
- Supporting safer movement of ships through busy waters
- Helping to solve the problem of unfamiliar bridge equipment
- Increasing the operating window in poor visibility and at night
- Replacing extremely expensive laser docking systems
- Supporting the training of new pilots
As pilots become less immune to prosecution, they must prove they have used all available
tools to help avoid an accident. PPUs are such a tool, and are becoming increasingly
accepted by the piloting community.
The cost of a PPU is quickly recovered due to the increased operating window they provide.
The risk of expensive accidents is also minimised.
How they work
A PPU provides a real-time true-scale image of the vessel overlaid against the background of
the official chart for the area.
It does this by using GPS receivers to pinpoint the position of the PPU equipment and the heading of
the ship, and using smart software to create the image on screen.
Improving accuracy
There are several levels of accuracy for real-time position and heading information:
- GPS
- DGPS
- RTK
Each method uses signals from satellites and/or ground stations to provide data to the
PPU. They all give a different level of accuracy, depending on what is required for the situation..
As you move up from GPS, through DGPS, to RTK systems, you achieve increased positional
accuracy. Along with this increased positional accuracy, the most significant benefit to the pilot
is increasingly smooth velocities, calculated from one second to the next.
In reality, it is the better (smoother) velocity calculations that is of greater benefit to the pilot
rather than the positional accuracy itself.
ยป Click here for a comparison of docking systems.
PPUs Today
The best PPUs are wireless, weigh as little as 5kg and are set up in less than two minutes.
They are known as 'full-function', because they give position, heading and accurate rate-of-turn
data. They can also accept an AIS feed.
The best software is sophisticated yet easy to use. Although it has many useful features,
such as recording the passage and predicting the future path of the vessel, it will not distract
the pilot from the task. It is designed specifically for pilots and is regularly updated.
PPUs have been available for less than ten years. In the early days some manufacturers
suffered from reliability problems but this need not be your experience. Buy a Navicom
Dynamics PPU, place it on the rail and in less than two minutes you will have all the data you need.
involved with for years. Normally they go through endless teething problems before you get
anywhere near the promised results, but it worked straight away. I'm amazed how willingly
the pilots have adopted it; some of them were quite opposed to the whole concept."