Manually entering the indoor rowing distance in GCM is almost an activity in itself :)
On a 30 minute workout I went 6637 meters (6,64 km ~ 4.12 miles) according to the machine.
When editing in GCM, the first column gives you increments in meters, so you have to scroll A LOT to enter a decent distance. Takes a minute+
Second and third columns are decimals, which seem way excessive to a rowing activity, unless you want your data down to the last centimeter :)
Your pace on GC is displayed (at least in Danish) as ex. '2:16 minimum/500 m'. I guess it should have been correctly translated to '2:16 minutter/500 m'
Both app and web displays the strength icon when doing an indoor rowing activity.