One way to trip both a breaker internal to the boat and a breaker at the dock at the same time and to not trip the Diruptor breaker can conceivably be:
1. The breaker internal to your boat happens to be an RCD breaker in addition to being a regular breaker.
2. The breaker at the dock happens to be RCD breaker in addition to being a regular breaker, or, the breakers are joined in such a way that if the RCD breaker trips, it also disconnects the regular breaker.
This happened to Peregrinus. It was a current leak from a defective water heating unit. Both an RCD breaker internal to the boat and the dock's breakers would trip simultaneously. The Diruptor never tripped.
SM2K Nr. 350
Kaunos (ancient Caria), Asia Minor