Use the following steps to delete a dive log:
Login to your account. Click the “My Account” link in the top right, then select the “My Contributions” tab. Next, choose the dive log that you wish to delete from the list.
If you have too many items in your list, you may limit the items displayed to only reflect dive logs by selecting “Dive Log” from the contribution type dropdown in the search box and selecting “Apply”.
Once you're on the details page for a dive log, select the “Edit” link, then select the “Delete” button, and finally confirm the delete request.