yes, the hoses nee to be routed over boarrd and these are NOT to get air to the prop !!! They are only to break loose the flat surface of the notch to get on plane easyer !
it also realy does not matter if 1 or 2 !!!!!
The ball valves are not for how much air , they are in case a hose breaks so you wont sink !!

The way I understand it, the holes supply air to the notch, not letting pressure out of holes.... Good example is sticking your finger on top of a straw while it is in your drink and lifting the straw out of the glass. Breaking or relieving the suction at the top of the straw allows the fluid to pass on out the straw. The valves act like your finger at the top of the straw, controlling how fast you relieve the pressure and introduce air to the notch clearing out the stuck water. That was the way it worked on the bass boat, but I didn't have the valve. If one of you 38' or 42' want to trade dead even, I will confirm all this for you

This is some interesting info, learn something new everyday

I'm confused, so the holes take air from the bilge to the notch instead of air from the notch. Is this the same idea as the tube on top of a #6 drive?

No, the tube on top of a SSM drive ..no matter if 4-5-6 or arnesson ( all SURFACE DRIVES ) is to airate the prop/s !

This is to get air under the notch so the water does not stick to it and break it loose!

To the hose on drives , its to make the prop/s spool up faster when not on plane since they need air to work more efficient!

Pits 1313 posted a good example !

I have also seen on bass boats a tube to the top front of the cavitation plate, was always told the tube sucked air to the prop so the 2stroke could rev up to it's power band. My bass boat days are about 15 years ago, so not sure if that's the case now. If fountain put them there, they're there for performance

Same idea but the air is introduced from a threw hull by the bilge pump outlet

Now I know why I have several unused dumps on the side of the boat. Just found out that my Hose's are capped also. So when I get the boat out of storage I should run a hose from the pick-ups to the dumps.

YES !!!!!!

My 29 Fever has one of those in the notch also. Tried to find out where it went but could not see a hose coming off it from the inside. Need a Fountain expert here to give us some details.