The Succorfish SC2 VMS (hereafter referred to as “VMS”) unit is a single box with no external antenna which is hard-wired to the vessel. The units incorporate dual Iridium satellite and GPS/GPRS/GSM mobile technology to provide accurate positioning to within two metres. Outputs from the unit for each ping include; vessel name, position, generated date and time of ping, speed, course, whether a satellite was overhead at the time of the ping, and the date and time the ping was received. The unit calculates instantaneous speed for each ping and then assigns a ‘speed bin value’ in knots starting at 0 knots with incremental increases of 2 knots thereafter. These ‘speed bin values’ are what is exported by the system. VMS units were offered to fishermen on a voluntary basis with the most active scallop dredge vessels approached for inclusion in the project. There were 36 SSMO licenced vessels which fished for scallops, all of whom were written to regarding the project and its aims. Of these, 23 make the majority of landings and these vessels were actively approached to have units fitted. The first unit was fitted in Shetland in April 2013 with a total of fifteen VMS units fitted throughout the period of the project. A data sharing agreement (Appendix 1: Data sharing agreement) between the NAFC Marine Centre and each SSMO licence holder participating in the study was carried out in order to provide the fishermen with security as to how and when their data would be used. Fishermen were also provided with log in details for the Succorfish online database (see Section 2.2) so that they could view their own activity online. Initially the units were set to report every three minutes but this was later changed to every ten minutes with locational information stored in a secure database and accessed via the internet. The change in ping frequency from three to ten minutes was an operational decision in order to maximise the quantity of information relevant to the vessel activity and the aims of the project without losing valuable information on fishing activity. Pings were transmitted via satellite but in the event of no satellite coverage, the units stored the information until it was possible to re-transmit the data. This eliminated any information loss due to loss of signal.