There is good reason why some tours are more expensive. For starters I note that the Explore Group have smaller vessels,like they used to have when they ran an opposition ferry service against Fullers to Waiheke Island. Their smaller vessels have good manouverability and can fit through Hole in the Rock better. No guarantee that they can routinely do so though.
I see that with Fullers Great Sights using larger vessels in the BOI, to carry more passengers, they may be oversized to go through Hole in the Rock. Hence they may approach the gap to show passengers this feature and then back off for a more eco-tour experience with dolphins and the Otehei bay visit.
Explore Group also has a fast jet boat from Paihia. 1.5 hour tour including Hole in the Rock, if weather is suitable.
Edited: 2 years ago