Don't panic! MmM/3

Not quite Dad's Army but this trailer was part of a rusting collection of old farm type equipment used to service the  shell fish industry. Shallow draught boats used to harvest mussels etc would bring them to shore in boxes and tractors would pull the trailers through the shallow water to off load the cargo with their  "cranes". I think the legend is an instruction to the operator should the tide come in too quickly!!. A few hundred yards away was an excellent seafood restaurant - the reason for visiting the area!