Assuming these whales were feeding, it is logical to believe their motion in the water was relatively stationary. Judging from the whale blow in relation to the stationary mountains in the background, the movement of the vessel can be estimated. Now, I'm not an expert here but it appears to me the ship is moving through the scene at a pretty good clip. I bet over 10 knots or 11.5 MPH. They say the law is for not over 14 knots (16.1 MPH) around whales. Even the Princess Cruise line policy is for, in the Icy Strait area, only about 70 miles to the north of Kingsmill Pont, that their ships not to exceed 11.5 miles (10 knots) per hour when in this strait, the strait south of the national park, due potential whale activity. Perhaps these laws need changing.
The distance between the cruise ship and the whales is difficult to precisely determine here, depending upon type of camera lens and relative positioning of the two boats. However, it is pretty close.
Now assuming that the ship did or not maintain legal separation throughout all this is one thing, but common sense is another. What are the cruise ships up here for anyway, certainly not to get between ports A and B as fast as possible? What the public at large appears to demand is when something like this occurs is for the vessel to slow, way down, maybe even stop and idle the propellers. Allow the guests on board to enjoy the Alaska they paid to see. But no can do, imperative to make port in Juneau according to a sacrosanct schedule.
The cruise industry in Alaska has been taken to task for unsafe time constraints before. But then, human lives were in jeopardy. For instance, in 2015, after a fatal aircraft accident occurred trying to get back to the ship for a timely departure, the NTSB said this:
"Time Pressure. Another issue in this accident was the time pressure that was created by the agreement between the cruise ship operator and the sightseeing air carrier that if the carrier returned passengers too late to catch the ship, the carrier would be responsible, at its expense, for timely delivery of the passengers to the cruise ship’s next port of call, which might be several hundred miles away. In this accident the pressure to return the passengers to the ship in time clearly played a key role in the pilot’s decision to take a shorter but obviously more dangerous route back to the ship."
"The big picture would suggest that other participants are involved in this situation – the cruise ship operators – should work with the carriers in an effort to create a sightseeing program that eliminates financial incentives to carriers to take more risk. The cruise ship operators make the flight services available to the passengers, so they, in addition to the carriers, have a vested interest improving the safety of the sightseeing carriers by eliminating these adverse incentives."
Some suggest that the captain had no choice but not to slow down, I suggest that if the captain was concerned that reducing speed would also reduce rudder effectiveness, then the option of stopping the vessel would be desirable. Full reverse, when cruising at 20 knots, which they probably were not doing, would bring the ship to a complete stop within one to two nautical miles. This is not only what ship's officers have told me but one time on the Seven Seas Voyager we actually experienced it.
Then too, if he wanted to keep head, using differential thrust would have undoubtedly made the vessel swerve to the starboard more sooner than just using the rudders. In other words, full reverse on the starboard propeller and full ahead on the port.