Does the US Constitution Protect Privately Owned Warships?

I hadn't thought about it before, but Doug Loss commented on a Bridget Johnson column over at Pajamas Media that:

In point of fact, the Constitution tacitly condones the private ownership of warships, in Article I, Section 8, where Congress is given authority to grant letters of marque and reprisal, which means deputizing private warships into government service.

It seems to me that while not explicitly protecting privately owned warships as a right, it is a reasonable conclusion that it does. It certainly assumes that there will be privately owned warships.

So: naval guns, ship-to-air missiles, torpedoes, all sorts of cool toys.

"The Congress shall have Power To...declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;"