The bow wave of this vessel intrigued this non-maritime photographer, who felt that, as we had a Marine Architect Mate whose work adorns this gallery, we should seek an explanation. Following is DRG's response:
"I am writing the response without ever sighting the boat so my assumptions could be inaccurate. It appears that it is "on the plane" which means it has engines capable of pushing the boat faster than the maximum hull speed otherwise allows. (All boat hulls have a maximum hull speed, based on the amount of water the hull displaces, which is determined by the shape of the hull, the thrust of the engines and the size of the propellor.)

The boat loks to be about 15-20 metres and would more than likely have two marine diesel motors- probably something like truck engines.The max hull speed through water without getting it to plane is probably about 15 knots, so the engines have to be (about) twice as powerful as a pair of engines to keep the boat at maximum hull speed. To lift the hull onto the plane and to overcome the resistance of the water and the weight of the boat requires a sustantial exponential increase in power. Because it is throwing such a large bow wave shows it is using brute force to exceed the max hull speed, but can probably go faster than when you saw it. It may even lift higher out of the water and as it is in the busiest part of Sydney Harbour I doubt it is travelling at it's max speed.

If it is a rapid response vessel, it may have engines three times more powerful than required."