Question, which you might have answered before are you intending to use the jet in the surf??
The reason is that the intake must be in the water to keep drive and stearing. Have seen in some jet boats once they leave the water off the wave (obviasly need to throttle back as normal) no water.
On landing it takes a second or so to pump the water through the system where as other drives there is no lag.
Though if your boat is big enough ( can they ever be
) will the intake be out of the water, do want to fly her!