How to set watch face during swimming to see the heart rate

Received the watch 2 to day and took it for a swim workout in the pool (of course😁)

happly to see it rather accurately counts the laps and gives the average heart rate but only AFTER the training 😟

I wanted to do 4000 m (and I did..) but when starting the exercise the watch asked for the total of calories to be burned.

QUESTION 1: how to set the distance (rather than calories)??? When starting the exercise?

While training the watch face appeared when out of the water and gave the number of laps, total distance, total time of exercise and calories burned.

QUESTION 2: can you change the information presented during the swim to see the heart rate? (Rather than the predictable Calories)??

REMARK

For swim training the watch is a bit of a disappointment, since in swim training you normally do some repetitions like 10 x 100 start every 1:30 or 1:45. I normally use the Garmin swim watch to take the time (press button when starting 100 m and press again upon arrival) the clock then briefly shows lap time and afte 4 secs continues so you can see when you have to start again (for example at 1:45). I hope there will be a third party solution soon for the apple watch 2, so that I do not have to swim with two watches....