I have cropped the pictures to include only the paddlers as I am adding them so you can do some self assessment. What to look for ... are you in time? or are you rushing the sweep? or are you lagging behind? are you the mirror image of your partner? (position-wise) are both your arms straight as you reach forward to the catch? or is the top arm bent down at the elbow is your body rotated in as you reach forward or are you looking at your blade? are you burying your blade completely? are you pulling back too far?

looking good - all really focused

accelerating that first 500m - right at the end of a session 2'48"   Phew.