Hi Dan~

The set to 80 volt sticker means…Set no lower than 80 volts for low speed…High speed is Unrestricted & Non-Adjustable..

Meaning that with the knob in the fully clockwise position, the speed control is passing thru full line voltage…

If you want to set low speed there is a hole under the Red sticker that you can either peel back the sticker or just punch a hole in it to gain access to a pot (small flat blade screwdriver) to set the low voltage with the knob fully counterclockwise…

They put the set to 80 volts sticker there to keep you from going lower & possibly icing the coil without enough air flow across it.

The staterooms on those boats don't seem to blow very hard but that's because Hatteras did a nice job of sizing the ductwork to make the system quiet…You want Volume of Air Movement not Velocity…Air Velocity is noise without much benefit, and as you comment…Those cabins are plenty cold…

The only time I would jumper out the fan speed control would be if it failed not allowing the fan to run (and I didn't have a replacement available)

Steve~

Digital Controls are the answer for many reasons…

But your 2 speed blower/evap will either need to be changed out to a newer model with a variable speed motor, or you will have to use Cruisair controls…

None of the others I know of can operate a 2 speed motor.

The newer Evap/Blower would be quieter overall though…Especially with the auto fan speed of digital controls that lowers speed with room temp…

Steve~