Abstract: A buoy has accelerometers and magnetometers for measuring characteristics of an ocean swell. The main plane of the buoy floats on and follows the motion of the free surface of the ocean water. A first accelerometer and a magnetometer are mounted on the buoy and oriented along the axis which is perpendicular to the main plane of the buoy (i.e. perpendicular to the surface of the ocean swell). A pair of accelerometers and magnetometers are mounted in the main plane of the buoy and are oriented along mutually perpendicular axes of that plane. The swell caused acceleration vector is perpendicular to the main plane (i.e. the free surface of the water). The accelerometer oriented perpendicular to the main plane measures the sum of the swell caused acceleration vector and the projection of the gravity vector along the axis of the buoy. The mutually perpendicular pair of accelerometers mounted in the main plane measure the projection of the gravity vector in the main plane of the buoy.

Abstract: A bucket using a box-like parallel-sided basket open at the front for dredging the sea bottom to collect nodules. The basket has a bottom wall with front and rear cross-bars and a plurality of parallel spaced rods extending longitudinally of the basket between the front and rear cross-bars. A front part of the bottom wall includes a grill formed by a transverse front link supporting one end of a plurality of longitudinal spaced flexible elements which are inclined downwardly towards the front and stretched between the front cross-bar and the transverse front link. Large shoes are positioned on lateral sides of the basket for supporting the bucket on the sea bottom. The grill is situated between the shoes with the transverse front link positioned in such manner that it penetrates the sea bottom. The basket is positioned inside the shoes and extends to the external edges of the shoes. The shoes include brackets for connecting a dredging line to the bucket.