I'm not into any voodoo that prevents plundering. A fleet should be plunderable if it has danger no matter what. The protection a voodoo card could offer should be limited to voodoo, skirmish and intelligence.
By "voodoo" I mean cards that target a fleet or maybe cards that target a ship in that fleet
By "skirmish" I mean reducing the effectiveness of the being skirmished but not preventing it entirely. Eventually fast ships should run away from skirmishes with high escape % so this proposed voodoo card would not be needed.
By "intelligence" I mean showing up on Spy Network Reports and Trade Master Reports. It's intangible but but extremely valuable to hide your vulnerable fleets from prying eyes.
I propose this:
name: "Stealth Fleet"
rarity: rare
100% piercing
turns: 8
duration: 48 hours
action: Cast on a fleet with no danger rating and no active voodoo: that fleet cannot be targeted by voodoo that targets a fleet. That fleet will not appear in Spy Network Reports or Trade Master Reports. That fleet can still be effected by voodoo that targets the owning player such as Fugitive From Justice, Favorable Winds etc and can still be seen in Port Gossip. If skirmished, that fleet has an additional 25% bonus to escape the skirmish. That fleet can't plunder a fleet as long as it is under the effect of "Stealth Fleet" but it can be plundered by another fleet.
-Captain D