| Using a narrow apple corer, make a hole at the stem end and scoop out the pulp by twisting it round, being careful not to break the skin. |
| Remove the core from the base, using a corer or a small melon baller. |
| The amount of sediment collected depends on the length of the corer, the size of the main weight, and the penetrability of the bottom. |
| A clamp attached to the corer is used to bring it to the surface with a winch installed on the boat. |
| Essentially undisturbed cores of lengths up to 200 metres have been obtained with this type of corer. |
| Rinse the outside of the grab and corer, paying attention to potential washout of the sediments inside. |
