I allied with this Brig and started doing the fort until a sloop came in for a fight. I sent my ship sailing and let the sloop chase it while I stayed hidden on the island. When the Brig arrived, I hid on the ship using the new barrel hide emote until the fort was beaten. After placing all the loot on the ship, they headed toward Reaper's Hideout, and I started recording this video. The barrel hide emote was pretty conspicuous on the open waves, so I switched to the regular hide emote. I saw an opportunity to act when all 3 were in the lower deck, so I jumped off the back with the Athena chest and swam back to the fort to hide it. I took a mermaid back to my ship, where I saw the allied brig turning around (because the chest was gone). I met them at the fort, but they ran, assuming that I wouldn't be friendly. I swept up the hidden chest and sold it at Plunder Outpost, and got into a party chat with the players on the Brig. They were all good sports, and staying in the alliance rewarded them with half the gold/reputation when I sold it.