'Not sure what you mean by private vessels.......
Where are the French doors exactly, and what is wrong with them?
What are private vessels?
private vessel means any motor vessel that is not engaged in business
Can you give more information?
veranda ? mezzanine? piazza?
You can add static cling privacy film
what is wrong with them? too big of a list of things to fix need to be more specific
You can add a translucent window film if you are looking for privacy.
I have no idea what you mean by a motor vessel not engaged in business. Is this for some sort of automatic door? You need to use more common terminology.