A passenger onboard today called an independent organization while in transit to report an incident that caused the vessel to have to "come to a stop." The passenger reported more. The vessel continued on with the voyage. The passenger and others alerted authorities. The vessel would be due at Kahului in a few minutes (~9:30am). Regardless of what happened, I remind all of the following requirement, as this will come up again:
From EO 07-10:
6. The company shall agree that any vessel's Master shall document and report any collision or whale approach less than 100 meters from the vessel, that in the event of a collision, the company shall document observable damage or injury to the whale and, if safe and possible, remain on scene with the whale until rescue response arrives, and within twenty-four hours of any whale collision, provide a detailed written report of the collision to the Director of Transportation and the Chairperson of the Board of Land and Natural Resources.
Of note, the vessel was only dealing with 7 - 8 ft. open ocean waves at the time and location of the incident. See here for those conditions and here. The vessel has had difficulty with deck-slamming in vertical movement on waves larger than this, but not significantly with lateral movement in smaller waves. Lateral movement is not likely to make the deck-slamming noise. Also, situations like this at this time of year would likely involve a pod and not just one specimen. To affirm these types of situations, it will be necessary for passengers to take pictures if at all possible, although this will be hard to do as there is a blind spot 50 to 100 yards off in all directions for passengers and from the center of the bridge. As a result, on close approach, even the bridge cannot be certain of contact or not.