Currently, Swim.com only supports logging open water swim data via manually entering this data through our mobile app or open water data generated by a Garmin or Suunto device and shared to Swim.com via account links to Garmin Connect and the Suunto mobile app.
To enter open water data into your swim log, open the Swim.com mobile app and with either the Progress or Feed tab selected at the bottom, touch the "Add Activity" icon in the upper left corner of the screen. Start by adding a title to the swim. Then, leave Swim as the chosen activity in the first drop down. On the second drop down, which is defaulted as "Pool", adjust this to "Open Water". Continue to fill in any applicable details and then save the activity.
A few notes on open water swimming:
With open water swim data recorded by a device, it can be hard to judge your improvement and progress based on a day-to-day basis.
This is because swims performed by the same person in the same body of water on different dates are subject to varying tides, wind, water and air temperature, currents, etc., which could provide a slower time result even if you have actually become more fit and are swimming faster and in turn make it harder to see if you are improving. Also, many times two swims of the exact distance in the same body of water will not record the same distance because each time the watch is submerged it loses contact with the satellite and tries to regain each time it is out of the water. There is about a 10% +/- margin of error.
Additionally, open water swims are hard to compare on leaderboards, because two swims of the same length or course in different bodies of water are not entirely comparable because of differences in tides, wind, water and air temperature, currents, etc. For example, a person swimming in warmer water with a wetsuit and a tide or current pushing them will swim the same course length a lot faster than someone without a wetsuit in slightly colder water who might be battling a headwind.
Some watches that Swim.com supports have both an open water and a lap swim mode. Open water swim files from devices OTHER than Suunto and Garmin will currently be rejected by the Swim.com system because they are unable to parse the data.
Open water and lap swim tracking modes on watches differ in that GPS records the distance for open water while lap swim distance does not utilize GPS in any way and is determined by data collected by through the device's internal accelerometer, a pre-programmed course length, and the motion algorithms programmed within the device's app (whether native or Swim.com).
In order to get an accurate result for lap swimming, the user must program in the correct course length of the pool because the motion pattern generated by a swimmer pushing off the wall with his legs (rapid acceleration after a pause in stroke pattern) during a flip turn or wall push off is what signals to the algorithms that you have completed a length. In open water swims, that motion pattern is not present and that is why a distance cannot be calculated in this manner and is what makes GPS necessary.