Forerunner 945 shows very little calories burned when swimming is finished.

Thanks for your answers. I'm a new garmin user, I don't know everything. There is a drill mode on my watch, but I didn't run it because I don't know what it means.

From what I see, I think there is a problem in the algorithm at Garmin anyway. The active Calories are indeed far too low, for the heart rate you have during those 37 minutes, regardless of the type of the activity or the stroke type. It should be much higher anyway. Only Garmin Support can help, but I am little bit afraid, that the first level support will not be able to see that there really is a problem on their side, so you may need to insist longer time, and try to escalate the case to a higher level of the support, closer to the developers.

I used the drill training mod today. and the result is worse. I stayed in the pool for 50 minutes and I swam actively for at least 30 minutes. but it says 9 calories.