typically the descent of the sampler is slowed as it approaches the seabed to minimize disturbance of the bottom and to insure that the seabed is encountered at the proper angle.
For most samplers, it is best to slowly retrieve the cable until the jaws are fully closed and the sampler has been lifted from the bottom, insuring that the full weight of the sampler is used to cut through the seagrass and sediments, and the sampler remains properly oriented.
Retrieval of the closed sampler may be made at maximum winch seed.
However, some samplers (e.g., Shipek grab) allow washout and loss of the sample under some conditions.
This can especially occur as the sampler is raised above the surface of the water and pressure from water trapped inside is forced out.
After the closed sampler is brought on board, its contents can be subsampled with a corer to insure a consistent area/volume is sampled