Aberdeen Explorer aground. The approaches to the lock gates were tricky and had to be finely judged. Many vessels found themselves stranded on a falling tide and had to wait for the next one so that they could continue. Fortunately the channel is bordered either by sticky mud or the hard sandbank known as Tiger's Tail. Vessels grounding very rarely came to any harm. The notable exception being the Spanish trawler Erimo. She grounded on the shoulder of the sandbank and capsized into the channel as the tide fell.