Underground river hydrogeological condition detection ball
Groove-shaped keel bottom plate lofting method and groove-shaped keel bottom plate machining method
Portable marine observation device matched with broad-shore ocean current meter
Large intelligent unmanned feeding ship of triple-hulled vessel structure
Wireless data transmission type sea wave height measuring device and measuring method
Accurate positioning device for underwater surveying and mapping and positioning method thereof
Projection line control method for inclined plate installation angle