Note the criss-crossed wave pattern behind the island.

The rudder blade (11) is supported on the trunk pipe (200) by a lower support (21) and by an upper support (22), which is offset to the lower support (21) along the trunk pipe (200).

In this manner a rudder for ships is provided, said rudder enabling the absorption of bending forces exclusively by the trunk pipe so that the rudder post must not absorb any bending forces.

rudder tube: tube through the hull at the stern of the boat and keeps the axis of the rudder (the stuff that makes the boat turn).

So to the most curious: rudder tube (1) was drilled under the waterline (2) and the leak filled a crashbox (3) rear engine.