as all have said a hard lesson to learn ihave been caught out there once by the tide one of my fellow club members had invited us to go from there in our boats, so all preperations being done we towed two boats down there mine being a 21 footer launching was fine and we set off after lunch the guy was not heard on the vhf anymore so about five we headed back in , to find there was no water for 8 to 10 feet below the slip and as you probably found out there is a large lip at the bottom of the slip as like yourselves we found the people there were all quick to help and a 4x4 came to our aid also we found out why our x buddy was no longer on the radio he had gone home and not told us, but having said all this kimmeridge can be an excellent place to fish but no fish whether on boat or shore is worth risking your life for, and no matter how much planning you think you have done ,something can always go wrong .so my tip for the day is if something doesnt feel right look right head for home and go another day.