Definitions for "Puddles"
Keywords:  oar, swirls, whirlpools, rower, whirls
The swirls of water left by the stroking oars. The distance between sets of puddles (spacing) is a measure of the boat's pace when adjusted for different stroke rates..
whirls left in the water caused by the blade as the rower pulls
The marks left by the blade on the water after the release.  The puddles indicate the “run” of the boat by showing how far it has traveled since the previous stroke.