With the increasing use of maritime Portable Pilot Units (PPUs), the International Maritime Pilots Association (IMPA) decided that it was advisable to draw up guidelines on the design and use of PPUs to ensure:
a) That Pilots or Pilot associations could be aware at the time of acquiring PPUs that the device fulfilled basic requirements of professional marine navigation equipment;
b) That manufacturers and suppliers of such devices were aware of standards normally used for ships equipment and relevant to the needs of Pilots; and
c) That basic functionality of such devices were easy to explain to Pilots and others.
These guidelines are not intended to be used as a detailed specification for PPUs as it is clear that the arrangements for Pilotage are different in different Ports and Harbours and that in some instances Pilots may need special PPU features due to the navigational constraints in that area.

1 Scope
These guidelines cover Portable Pilot Units (PPUs) carried onto a ship by Pilots. A PPU is a pilot’s tool that assists in the safe navigation of the piloted vessel.
It does this by providing navigation sensors, such as GPS and differential GPS along with heading and rate of turn sensors, latest electronic chart information and display and ability to show AIS targets from ships own AIS receiver. Other information can include tidal and depth information when this information broadcast locally and any other information which is specific for a particular port.
Typically PPUs can be set up quickly on the Bridge wing with simple deployment of the navigation antennas, and connect using wireless technology to a laptop computer positioned where the Pilot normally navigates. Connection may also be made to the ships AIS transponder to allow display of other ships and navigational aids where thay have AIS facilities.
2 Abbreviations
AIS Automatic Identity System
ECDIS Electronic Chart Display and Information System
GPS Global Positioning Sytem
IMPA International Maritime Pilot Association
PPU Portable Pilot Unit
3 References
Within this document a number of references are made to International Standards which apply to equipment and facilities on ships that meet the requirements of the International Maritime Organisation SOLAS regulations.
IMO Convention for Safety of Life at Sea (SOLAS): 1997 as amended
IMO Resolution A.694(17): 1991, General requirements for shipborne radio equipment forming part of the global maritime distress and safety system and for electronic navigational aids
IMO Resolution A.813(19): 1995, General requirements for electromagnetic compatibility (EMC) for all electrical and electronic ship’s equipment
IMO resolution A.830(19):1995, Code on alarms and indicators
IMO Safety of Navigation Circular 243 Guidelines for the presentation of navigation-related symbols, terms and abbreviations
IEC 60945 Maritime navigation and radiocommunication equipment and systems – General requirements – Methods of testing and required test results
IEC 61162 series Maritime navigation and radiocommunication equipment and systems –digital interfaces
4 General requirements
4.1 Electromagenetic compatibility
As PPUs will be used by the Pilot on the bridge of a ship, it is important to ensure that they do not interfere in any way with the existing bridge navigation equipment. The typical PPU (a simple laptop computer) and PPU-related equipment such as an IMO-compliant GPS unit and the ship’s IMO-required Pilot Plug do not present electromagnetic interefence problems. Nevertheless, PPUs should meet the following extract from SOLAS Chapter V, regulation 17, especially c) below.
a) Administrations shall ensure that all electrical and electronic equipment on the bridge or in the vicinity of the bridge, on ships constructed on or after 1 July 2002, is tested for electromagnetic compatibility taking into account the recommendations developed by the Organization. (Res A.813(19))
b) Electrical and electronic equipment shall be so installed that electromagnetic interference does not affect the proper function of navigational systems and equipment.
c) Portable electrical and electronic equipment shall not be operated on the bridge if it may affect the proper function of navigational systems and equipment.
Additionally IMO resolution A.694(17) paragraph 6.1 states
(A.694/6.1) All reasonable and practicable steps shall be taken to ensure electromagnetic compatibility between the equipment concerned and other radiocommunication and navigational equipment carried on board in compliance with the relevant requirements of chapters III, IV and V of the SOLAS Convention.
Tests for Electromagnetic compatibility are common in the electronics industry for all equipment even that which is used at home. The particular levels for tests suitable for ships equipment may be found in IEC 60945.
Annex C of IEC 60945 describes the sort of Electromagnetic environment found at sea and the types of tests appropriate.
4.2 Safe bridge design
SOLAS Chapter V regulation 15 is to do with principles relating to bridge design, design and arrangement of navigational systems and bridge procedures.
These regulations have been developed to:
a) facilitate the tasks to be performed by the bridge team and the pilot in making full appraisal of the situation and in navigating the ship safely under all operational conditions;
b) promote effective and safe bridge resource management;
c) enable the bridge team and the pilot to have convenient and continuous access to essential information which is presented in a clear and unambiguous manner, using standardized symbols and coding systems for controls and displays; and ..
d) minimize the risk of human error and detecting such error, if it occurs, through monitoring and alarm systems, in time for the bridge team and the pilot to take appropriate action.
Any PPU brought into the ships bridge environment should be consistent with these principles.
4.3 Hydrographic displays
Although the display on a PPU of hydrographic charts need not meet all the requirements of a SOLAS ECDIS, it is advisable if the chart had the following attributes:IMPA
a) Uses IHO symbology as defined in IHO publication S52:
b) Uses where available IHO official chart data; and
c) Has available the same colour palettes as will be used in ECDIS.
4.4 Compass safe distance
IMO resolutionA.694(17) in paragraph 6.3 defines compass safe distance as follows:
Each unit of equipment normally to be installed in the vicinity of a standard or a steering magnetic compass shall be clearly marked with the minimum safe distance at which it may be mounted from such compasses.
IEC 60945 goes on to say that - portable equipment shall always be marked.
ISO 694 defines "vicinity", relative to the compass, as within 5 m separation.
4.5 Interfaces
4.5.1 AIS data
The Ships AIS equipment is fitted with a “Pilot Plug” from which AIS data may be obtained. There has been some confusion on the wiring of such plugs and the transmit and receive data lines can be reversed. Pilots should be aware of these and other potential problems and deficiencies with data obtained through the Pilot Plug.
4.5.2 Other Data on the AIS port
Other data is available on the AIS Pilot plug however ships Gyro heading is only passed to the AIS at a relatively slow rate from some older gyros and may not be accurate as traditional gyros did not transmit actual heading just changes. A converter is often fitted in these circumstances to provide actual heading for the AIS, but of course this has to be initialised before sailing.
4.6 Ruggedness
The maritime environment is a tough one and especially tough during pilot transfer. It is recommended that PPUs are designed in accordance with the environmental requirements defined in IEC 60945 for similar portable equipment.
IEC 60945 defines 4 categories of equipment:
a) portable;
b) protected from the weather;
c) exposed to the weather; and
d) submerged or in continuous contact with sea water.
Although the PPU may have a waterproof container, any equipment used on the bridge wing should at least comply with the requirements defined by a) and c). Laptop computers will generally be used in a protected environment and should comply with a) and b).
4.7 Intrinsic safety
Portable electronic equipment, used on oil tankers, LNG carriers and similar ships, that contain transmitters such as hand held VHF radios are limited in power output to less than 1 Watt and are often tested and certified as “Intrinsically Safe”. This process is very costly and ensures that no sparks within the equipment from on/off switches etc. are likely to cause explosions. It is unlikely that the equipment configured as a PPU will have these problems.