Chris Parsons knocks on the surgery door to which Martin answers. When they walk in, the surgery is full with patients.
Al jumps into the sea to help trapped Chris Parsons.The reverse angle shows Al's jacket is already wet before he ducks under the water. His costume had not dried between takes.
The opening chat between the Doc and Louisa is supposedly occurring at 1:00 a.m., but bright daylight is evident from two windows - behind the doc and to the right of the frame, then behind Louisa.
When Chris Parsons is pulled from the sea, he clearly has a wet suit under his clothes.