It's interesting to look at Hobie's different hull designs and see how they develop speed.
The older generation Mirage Tandem has a waterline length (LWL) of about 13.5 feet for a "hull speed" of 5.7 MPH. In the picture below, OffRoad
and some deadweight are pushing it pretty close to their max of 6.8 MPH, beyond which it refused to go. It exceeded its hull speed with the help of a couple of pair of Turbofins but, as you can see, it is stuck in its own "wave trap".
The Adventure uses a different hull design and is more successful at avoiding the issue. With a LWL of about 15.5 feet, the "hull speed" is 6.1 MPH. With only 40% of the power used to drive the tandem (one set of standard fins), it can top 7 MPH; with a set of Turbofins, it can do at least 7.8 MPH and not look like it's stuck. As pictured below, The Adventure is running close to its hull speed. Notice how little water it's pushing!
Aside from a small turbulance behind the rudder, you'd hardly notice it was moving.
It would seem that Hobie's newer generation hulls are opening up the speed envelope, and the Turbo fins are able to exploit it quite effectively.