A repeat seasonal hydrographic survey of the Balearic Sea, monitoring the Ibiza and Mallorca Channels. 35 CTD stations were carried out over 4 days, 25 stations formed three transects across the Ibiza Channel (IC), while the remaining 10 stations formed a Mallorca Channel (MC) transect on day 4. Two additional stops allowed for maintenance of the Ibiza Channel Buoy and the deployment of an SVP drifter.