This dataset comprises hydrographic and meteorological data transmitted in near real time from unmanned surface vehicles (USVs). Also included are hydrographic profiles through the water column obtained from submarine Slocum gliders, upon recovery. Data from these platforms have been converted into the international 'Everyone's Gliding Observatories (EGO)' exchange format. The dataset is supported by barotrophic tidal current imagery. Hydrographic data were obtained from two geographical regions. Firstly, from a transect extending from the Isles of Scilly out to the moored Carbon And Nutrient Dynamics and Fluxes Over Shelf Systems ('Candyfloss') Array in the Celtic Sea. Subsequently, a more localised survey was carried out in the English Channel, south of Plymouth. The tidal image data span the period 1st October to 21st November 2014 (15 minute intervals). Autonomous platforms were deployed between 1st and 26th October 2014 (Phase One, Celtic Sea), subsequently between 4th and 7th November 2014 (Phase Two, English Channel). Data were collected as part of Marine Autonomous Systems in Support of Marine Observations ('MASSMO'), contributing to the Exploring Ocean Fronts project. Tidal images are a product of Proudman Oceanographic Laboratory Coastal Ocean Modelling System (POLCOMS) simulation runs. MASSMO was carried out as a trial of new autonomous technologies and to collect scientific data, including observation of marine life. The dataset acquired provides valuable oceanographic and meteorological measurements including a traverse of an ocean front. MASSMO was a collaborative effort involving various UK laboratories and commercial organisations, coordinated by the National Oceanography Centre (NOC). This data archive consists of measurements made by wavegliders operated by NOC and the Centre for Environment, Fisheries and Aquaculture Science (Cefas), the MOST Autonaut and Slocum glider units 398 and 400, operated by NOC.