Investigating with AIS data

This blog post was updated on 7/6/2019 

MarineTraffic meets Paul Whyte, a London based marine investigator with leading international maritime consultancy LOC and finds out how AIS data collected by MarineTraffic is used to investigate accidents and resolve commercial disputes

Shipping accidents unfortunately happen all too often. Overcrowded shipping lanes, overtired or poorly trained crew, equipment failure and poor weather can all contribute to the loss of ships and lives. According to the Hamburg headquartered International Union of Marine Underwriters (IUMI), around half of the world’s total losses are caused by bad weather; around a third by grounding and under 10% by collision. Understanding exactly what happened and crucially the exact behaviour and track of the ship through its AIS data can be key to preventing a future tragedy.

But it is not only sinking ships that keep marine investigators busy. Shipowners and charterers will sometimes disagree over the fuel bill or will disagree on any number of other complex issues and ultimately someone needs to decide who will bear the cost. It is the job of the marine investigator to put the pieces of the puzzle together, present as clear as possible a picture to allow a decision to be made as to where responsibility lies.

The City of London is home to companies from across the maritime spectrum, many of whom will have reason at some stage to seek the advice and counsel of a maritime consultant to help resolve a dispute or investigate the cause of a shipping accident.

One of the leading investigators in this field is Paul Whyte, a master mariner and consultant at LOC London with 37 years’ sea-going experience.

According to Paul Whyte, speed and performance disputes are ‘bread and butter’ in the shipping world and AIS data is important in helping resolve these cases.

Vessel Timeline Report AIS Data
MarineTraffic Vessel Timeline Report

“These disputes occur when the speed and performance figures given by the owner of a ship are disputed by a charterer, who may attest that the ship in question uses more bunkers when sailing at a certain speed than declared by the owner. Over a long charter period, this could result in the charterer footing a much larger bunkering bill than expected and subsequently seeking financial redress from the owner.”


He says that in such a case, AIS data would be used not to calculate the distance travelled by the ship (ships usually measure this accurately) but to see what the ship actually did. Rather than setting a sensible course, the ship might have sailed against major currents and done nothing to avoid an adverse weather area with a rough sea sate, working its engines harder than usual, explaining increased bunker consumption.

When a ship has been involved in an accident in port, perhaps coming into contact with another vessel or hitting a fixed object such as a crane, AIS can be used by investigators to construct a picture of port activity.

Paul Whyte says: “Looking at AIS data, it is possible to tell whether the port was quiet or busy at the time of the incident, how many vessels were present, which were stationary and which were moving. This information can then be used to cross-check and dispute witness statements, or support them as the case may be.”

Similarly with collisions and groundings, AIS data can be used to provide ‘snapshots’ of information with a good degree of fidelity, allowing the movements of vessels to be worked out in relation to obstacles such as rocks and sandbanks, or other vessels. In the past, besides the marks of physical damage, investigators were left only with written statements.

The navigational equipment on the bridge of a modern ship would be unrecognisable to previous generations of seafarers.  A combination of electronic charts and AIS has revolutionised navigational officers’ lives, but according to Paul Whyte, this has brought new problems.

“All too often navigators are losing their situational awareness because they are too focused on what’s happening on their screens creating information overload whilst pre-occupied with navigating from one way point to another without appreciating the width of safe water.”

He says that electronic bridges are giving some officers a false sense of security and notes that ships are passing closer to each other than ever before in narrow channels and waterways. “AIS should not be used for working out safe passing distances of other ships or navigational marks,” says Paul Whyte.

Crucially, AIS equipment must be set up correctly and kept up to date. Paul Whyte cites the case of ships which have changed names, but whose crews haven’t also updated their vessel name on their AIS.

Related: Voyage and vessel information that can be changed on AIS transponders

“We have seen cases where ships in the vicinity are calling out over the radio to a particular ship by its former name and therefore are being ignored leading to a clearly avoidable incident.”

To ensure transmission of correct AIS information which will greatly help prevent any collision as well as any potential investigation, ship operators and crews must ensure that installation requirements set by equipment manufacturers are followed. These can be found in installation guides, provided with the equipment, to update voyage related and static information.

There are three basic rules that should always be remembered when positioning antennae and cables:

  1. Mount the VHF & GPS antennas as high as possible on the mast / superstructure of the vessel.
  2. Make sure the UAIS antennas are not in the same horizontal plane as the marine DSC VHF and / or RADAR transmission lobes.
  3. Make sure the RF cables running to the UAIS transponder do not run parallel to any high power transmission line within the vessel. Also, the cables should be installed in a straight line and there should be no loops in the cable run.


New call-to-action