Italian frontier patrols

I'll add one more to the list; lying in wait - to start up and pounce (retractable sea dagger fins would help here).

The hovercraft in displacement mode (off cushion) will get rocked around a lot with it's flat bottom. It will also take a while to get up to hump speed, whereas a regular patrol boat can take off rather quickly by comparison.

On the range issue, I'm not so sure as hovercraft sip half as much fuel as boats, but that only covers while at top speed.

A boat can patrol at a lower speed and consume less fuel, difficult for a hovercraft which has to maintain a certain speed to keep from dropping into a hole in the water (related to hump speed).

If you have large mud flats or ice near waters edge, or hull ripping/beaching obstructions under the water then in that tiny operation envelope the hovercraft is for you.

I also imagine rough weather operation being a factor; if the bad guys know all they have to do is to wait for choppy/stormy conditions then there is yet another disadvantage for the hover.

 

Whenever the Marina Militare wants to get serious they send one of their Sparviero-Class hydrofoils that will do 55 + knots in most conditions the Med can dish out.