If you are looking for equipment for this type of work then you should look at the Tritech Bathy unit which is an ROV mountable device that gives an integrated measurement of the total water depth, derived from ROV depth, altitude, water temperature and salinity. this unit gives a single point reading.
for more complex surveys you may want to look at multibeam systems from Reson or Kongsberg.
either way you would need some software to produce a bathymetric chart.
