Nice!
I also have Garmin, one for swimming and another one for running but I prefer the Apple Watch because of the way it automatically transfers everything to my iPhone. I don't even have to do anything...and it captures all sorts of info like elevation, heart rate stats, splits stats, etc.
It appears you and I have similar swim times. I did my 2600m in about 1hr, 5 mins with no breaks.
Here are the stats from my last swim before the gym closed down, I never go all out because I was planning to swim for over 1hr (but then got cramps and had to stop early

). With the Apple, I can see times for 100m, 50m, 25m, etc.
View attachment 111980 View attachment 111981