I bought a used 16- I know little to nothing about them. I have had a blast the last 2 days on it.

My question this time. I have steped the mast, and tightly attached the front line (forestay?) to the adjuster in front between the bridles (to the two tips of the hulls).

I then snugged up the two shrouds. All three look FAIRLY tight at rest. Now when sailing, the down wind shroud looks VERY LOOSE - (of course the mast is being pushed that way) so I assume this IS normal? Just checking to be sure it's safe.
The mast seems snug, but rotates in the receptical easily.

Or should both shrouds be SNUG/TAUGHT all the time while sailing?