For creating/editing new bodies of water with the current beta update of VR Sportfishing there are some new parameters to include in your *.lak files:
// Water type: Use one of the following values:
// pond, small_lake, medium_lake, large_lake, stream, medium_river, larger_river
// Maximum water speed of a river, in feet per second.
// Do you want NPC boaters on the water?
// Do you want players to be able to walk and fish from shore? Saying yes
// eliminates the dock fishing option.
// Do you want players to be able to fish from boats?
// Do you want the game to automatically add trees & plants? If you're adding
// objects with the new system you should say "no" to the auto vegetation.
// Average water temperature - Rivers and streams are often colder than still
// waters the same size would be, due to cold springs, dam discharges, etc.
// Setting the ave temp to 50 and the adjustment percentage to 60 is like mixing
// 6 parts 50 degree water with 4 parts of water at the temperature that still
// water would be at that time and place.
There will be more parameters to come in the next few beta updates.