Open water swimming on Instinct

Hey guys,
has anybody been able to figure out how to make the Instinct be as accurate as possible with open water swimming?
For now i really have no idea how this works.
Before my swim i get GPS signal and get into water - swim various styles - does not matter and all i can see is 0 for distance/speed, etc (obviously GPS does not work under water). When i stop to rest, or finish my activity - with hands above a surface - Instinct starts to slowly catch up - meter by meter a distance is growing. Water only just now got warm here so i have not had a change to test it much - but as far as i can see a distance - even if my break was 5 mins long - never stopped to increase with GPS on - maybe it stops after it catches up, maybe not - i dont know. What if im in rush and need to switch to another activity - how long i need to wait until it catches up. What is my start and stop point is the same place - i think the distance might be 0 meters than..?
Anyways - anybody using Instinct intensively open water? Some tips i should follow to make it as accurate as possible?