I have a 2007 250 PRO XS on a 21X2. 64hrs

When I'm setting at idle or in gear at idle it seems the air pump or compressor is louder than it should be.

When I'm in my boat and I there are other boats around their Optis sound like more of a buzzing noise.

My friend has a 05 225 Opti and I cant hear his air pump when I'm in his boat.

It has sounded like this since it was new.

Is this normal?

Thanks
Jeff