SPOILERS for a pretty big event below, beware.
The event where the hole gets opened up is very cool, but the requirements to make it end are very specific and not intuitive. Approaching the hole seems to be discouraged, as the little machines shoot at you, but in order to end the event you have to basically get right up on the hole (and do nothing but look at it?). I had to look for a solution, because at the time I had already viewed the hole on the camera and flown a remote drown all the way to the bottom of the hole. I did not think there was anything to gain by going to it in person besides potentially getting killed and losing the event.