Launched by Sarah MacLean and family, bottle #4 travelled from Arbroath in Sarah's pocket firstly by car and then by ferry from Fionnphort to Iona. In Iona the bottle attended a Mendelssohn concert at Iona Abbey before it was launched finally into the waves from the beach.
Sarah and her family watched the bottle anxiously as they were not sure if the tide was coming in or out. However on the return ferry they saw the red top of the bottle bobbing happily away halfway between the two ports. This time now wondering whether the currents would take the bottle North or South.