1. reconnaissance/sketch survey: a survey made to a lower degree of accuracy and detail than the chosen scale would normally indicate. (IHO Dictionary, S-32, 5th Edition, 5219)
  2. controlled survey: a thorough survey usually conducted with reference to guidelines.
  3. examination survey: a survey principally aimed at the investigation of underwater obstructions and dangers.
  4. passage survey: a survey where soundings are acquired by vessels on passage.
  5. remotely sensed: a survey where features have been positioned and delimited using remote sensing techniques.