Offshore survey services are often provided from third party vessels, where they may need to share differential global navigation satellite systems, such as differential GPS (DGPS), which are also used to dynamically position the vessel.

Whilst usually convenient, such sharing can present potential operational problems relating to the control and performance of the system. Contractual disputes could also arise in any situation where the survey and DP users were different companies and where installation, manipulation or reconfiguration of the position system for either survey or DP use may impact on the performance of the sytsem for the other party.

It is therefore critical from both safety and operational perspectives that full co-operation is exercised between these two users. IMCA has developed these guidelines to address such situations. They set out basic definitions before going on to consider the differing requirements of both surveyors and DP operators. Going through consideration of the various technical and operational aspects, they conclude with a set of recommendations which provide good practice guidance to the industry.

Related publications:

• The shared use of sensors for DP and survey operations