Invisibile ships during privateering?

[Arioch]

What is up with the invisible ships in privateering?

occasionally I see a wake left by a ship unseen and release helm and grab a cannon

so that the ship can be seen (works in player mode all the time)

although unlike in player mode grabbing the helm and releasing doesn't do squat.

found out by accident that ramming seems to remove the issue.

Is this an intentional glitch that can be reproduced?

Also attacked a few ships without any armor and reduced them to zero and yet poof they got full health??

is this same glitch?

How is it done?