I read that when you exercise in water, as opposed to in the air on land, it takes twelve times the effort to move the water. The article said, that doesn't mean you figure out the calories burned during water exercise by multiplying land exercise by 12." The article was explaining why exercising in water burns more calories than the same movement on land.
If you are trying to find a comparison for your fitness tracker, I would focus on the "in the water" part, and find an similar exertion to what you are doing; and don't use the figures for the same exercise on land.
Being disabled with a spinal injury, being in the pool is the best way for me to achieve true cardio intensity. On land, the exertion becomes mixed up with pain and muscle spasms, and limited by my physicality.
I figured out the calories burned, to my best estimate, with each of the exercises I do in the pool - such as Doggy Paddle, Treading Water, Power Walking and Aerobics - and manually entered and saved them to my Favorites. That makes it very easy for me to post on my Fitness Tracker; plus, I can adjust the calories burned, up or down, if needed.
Also, I suggest, it's more important to get the minutes correct, and not to worry too much about the exact calories burned. While "Calories In, Calories Out" is the formula for weight loss/gain, we can't rely on just doing the math. Our bodies are affected by many other factors, on a daily and even hourly basis, which affect what the scale will say.
I LOVE the water... I can stand, and walk and run, and DANCE again!
So above all, HAVE FUN & ENJOY IT!!!