I know this has been discussed and answered before so my apologies as I cannot find the answer via search. I am going to start prepping for PADI DM this summer and in addition to the great suggestions here and the linked thread above, I am simply going to work on swim tests and times based directly on the requirements in the DM manual.
To that end, PADI seems to equate meters and yards without making an allowance for times. If I am correct in that understanding, why would I ever want to do yards instead of meters? On the 400M swim, doing it in yards would add an extra almost 40 yards in distance without an allowance for time. I have read that this is dependent on the DM Instructor's discretion.
Additionally, if the swim skills require "non-stop" do candidates general swim in a pattern around the edge of the pool (i.e. always moving forward) or do they go wall-to-wall and reverse themselves back and forth?