Total Hydrographic For Surface vessels with a significant draft, #Under#Keel#Clearance is critical. Total Hydrographic provides the information and accurate survey data for the shallowest depth in the navigational passage for you. At Total Hydrographic we collect... moreFor Surface vessels with a significant draft, #Under#Keel#Clearance is critical. Total Hydrographic provides the information and accurate survey data for the shallowest depth in the navigational passage for you. At Total Hydrographic we collect bathymetric data in a variety of different methods and equipment. https://www.totalhydrographic.com.au/services/bathymetric-survey/less