The high pressure hose is from your engine block. Probably T'd in with the oil line to your turbo. This allows the sender assembly to be mounted...
Something I always wondered about; Could it be possible to ad a hull section under a stage/platform like this? Offering the whole ship added...
Do you see the platform dipping down?
With two wires on the alarm switch, one of those wires may go to the water temp alarm switch like on a generator. Your alarm system may not be as...