Possibly not the best way to prepare for a 5k swim

Last minute preparation is an inadvisable way to go about preparing for a 5K swim.
However as I have not really been doing any continuous swims, I thought I’d have to do something.  So with the 5k swim on Sunday, my preparation this week has been:
Monday lunchtime: 2k focus on relaxed natural breathing.
Tuesday morning: 2.5k focus relaxed breathing and holding the core.
Tuesday lunchtime: 1k (to top it up).
Wednesday morning: 1.5k holding hips and core.
Thursday: rest.
​Friday morning 2.5k super easy slow swim; easy breathing, holding my hips and straight arms.  (I could easily have carried on as was sharing Petersfield Open Air Pool with just one other swimmer).
Saturday: will be a rest day
Sunday Evening: will be 5k.  It will be interesting to see if the preparation has worked.