If you observe this phenomenon, the first thing to do is to make sure you followed the route correctly and, in particular, that you correctly passed the buoys or gates that appear on the map.
Indeed, if you did not sail around a buoy correctly, your distance to finish will continue to be calculated according to this mark, and you will see it increase as you sail away from the buoy.
If this happens, you will have to go back and around the buoy properly.
Also, it is possible that your competitor's ranking displayed on your game screen uses data that is a few minutes old. In fact, your boat's data is displayed in real time, but other boats' data is refreshed less regularly. This helps us reduce the flow of data transmitted via the game, in order to offer you a faster and more fluid experience.