Supposedly you can open the ballast tank valve and use the boat speed with the large outboard to drain the ballast tank. Close the valve and Im not sure of exact speeds but its maybe 15 knts depending on loads, outboard hp etc. The boat is self righting with the ballast tank full but with it empty.. who knows. Once you get some water in the cabin, the boat loses additional stability.
So.. just a speculation but maybe someone was motoring with the ballast tank empty. This sounds like a bad idea so is possibly wrong so who know. You can see one rudder up (I think there are two) which also might indicate faster speed motoring.