They also have a boost controller and crank the boost up at planing speeds.

The nature of a centrifugal supercharger is that boost increases 1:1 with engine speed. In a boat you end up with not enough torque at planing speed and then wacking your rev limiter up top with more torque than you need.

You should for sure do this if you run a centrifugal blower.

That's not necessarily true. The nature of turbochargers is that when put under load (such as coming onto plane) they will spool and make boost independent of RPM. If an engine would need to have the boost "cranked up" to plane, it's a totally mismatched engine/turbo/gearing/prop package.

Boost with a centrifugal blower is engine speed dependent, but not a 1:1 correlation

Thanks

you don`t need those with a roots or screw, plenty of TQ on hand.