Oversize

From Horizon's End Wiki

Oversizing is the act of detecting a ship with more blocks than the class allows, and is often used to tow multiple ships together.

Any ship can be detected with 10% more blocks than the maximum allowed for the class, with a 50% debuff to ship power to thruster acceleration, shields, and weapons. The debuff is the same for any block count above the limit for the class. Speeder and Platform ship classes can be detected as oversize ships without any penalties.

Oversize ships are able to carry extra chests, allowing oversize ships to have slightly more storage.

When detecting a ship, it will warn the player if the ship is oversize.