RRS 'Challenger' Cruise 74B, 1-10 February 1991. Wave and current dissipation and sand transport in the Bristol Channel

This cruise was designed to study wave and current dissipation and sediment transport in a high energy regime. The study took place off Carmarthen Bay in the Bristol Channel in February, which is an area of strong tidal currents, frequently experiencing large waves including long-period swell from the Atlantic. 11 Moorings were deployed at the beginning of the cruise and recovered at the end, at two stations separated by about 10 nautical miles. The instruments deployed consisted of two STABLE rigs to measure the bottom boundary layer structure, two ADCP rigs with pressure recorders, two near-surface and two near-bottom S4 current meters, a WAVEC buoy, a Waverider buoy and a meteorological buoy. In the intervening period of about a week between deployment and recovery the area around the two stations was surveyed using sidescan sonar, echosounder, grab and core samples and CTD (with transmissometer) dips. An experimental suspended sediment profile rig was deployed. The ship's radar was also used to obtain wave spectra.