It is important for larger vessels to have a reliable navigational echosounder. 

IMO has issued special requirement to the perfomance for navigational echosounders via the socalled 'performance standards' which are to be followed in order to provide safety of the vessels. 

A navigational 'echo sounder' must fulfill the IMO MSC.74(69) Annex 4. valid for all cargo vessels above   300 GT and all passenger vessels of any size.  

FURUNO's famous FE-700 echosounder fulfill all the above requirements including the classification socities standards to an effecient and reliable echosounder.