Thats a good call Lloyd Turner...if you get off the boat at Satun with 2 land entries, the boat is on its way back before you get through immigration. They cant send you back anywhere
by the way, there are now only 2 boats a day each way from Satun Tammalung pier...they stopped one for Ramadan and have discontinued permenantly. They fill up early...the koh lipe ferry is full over a day in advance and when youre coming from Satun for the 10am...get here before 9.30am or they wont sell you a ticket...
you could go to the local amphur office and get a yellow book...its like the tabian baan that thais have. Go talk to the local amphur office and take your wife and any neighbour who knows you well as a witness...Im sure they will sort you out :-)