So I've not done session 1 yet for this week but that I overlooked that and went straight for an hours swim without the pull buoy. It was slow but this was partly because I was in a lane with even slower people! Many times I caught up and had to slow down dramatically and then wait at the end for a few seconds for them to move off. Also, on two occasions I stopped mid-length and turned back to break my position in the slow convoy.
I set off well at a 2:40min/100m pace but slowed to around 3:00min/100m through the 2km. Of course SPL crept up too. On the positive side, I felt less fatigued than previously, even though my final pace was a bit better. Progress again?