Specifically, the small armored dock can protect Schooners and Sloops, with a beefy 20M HP and an upkeep cost of 50 gold every 24 hours. The large armored dock has been adjusted as well, ramping up its HP total from 300K to 30M and a lowered 150 gold upkeep cost. Armored docks have also gotten a few other overall adjustments like stopping damage to NPCs and Tames on protected ships and a requirement for ships to not have taken or received damage for five minutes before receiving protection from an armored dock.
Content retrieved from: https://massivelyop.com/2020/12/07/atlas-tweaks-armored-docks-and-trading-with-its-most-recent-update/.