Garmin 910 data recording question

Did an ows today at a local park where there there is a roped off section about 100 yards long. After the swim it seemed to me that the recorded distance was considerably shorter than it should have been. When I looked at the map on Garmin Connect it showed many of the turns taking place 25-35 yards short of the endpoints, and I know I went end to end at all times. I checked the manual and see the 910 has two data recording modes, "smart recording" and "every second". Here's how Garmin describes them:Smart Recording records key points where the fitness device changes direction, speed, heart rate or elevation. This recording type allows the user extended record time given that it is recording less track points thus taking less memory to store these points.Every Second Recording records the activities information every second no matter if the unit changes direction, speed, heart rate or elevation. This recording type provides the user a more defined track log of their activity. However, record time will be reduced given that it is recording more track points thus taking more memory to store these points.I think the default is Smart Recording since it uses less memory, and theorized that it may not be wholly reliable for measuring this type of swim and wanted to reset to 'every second' mode. This is supposed to be possible at mode>settings>system>data recording. Problem is, I can't find 'data recording' on that menu. I upgraded my version to 2.6 but still not there. Is it available on your device? I go off course somewhere in this process? Is there another pathway?