Sanding gloss coat

So need some help if possible on my poly gloss coat, seemed to go on ok now started sanding with power sander at 400 grit wet, then went to 600,800,1000 all by hand but the surface has strange bumps and uneveness on one side of the board not the other particualarly towards the rail when you look down the board from nose to tail you can see the bumps but sideways on it looks perfect.

Is this because i hand sanded and created ruts or was it with the power sander?

flat is flat…if you don’t sand it flat it will look wobbly.    Sorry for the swaylocks proverb, but its true.   Machine sanders with flat pads will sand flat, but if you gouge it or don’t let it run true…it will do strange things.   As for hand sanding, the only time I hand sand is to remove small scratches…ie, 320, 400, 500 etc grit.  I leave the heavy grit to the machines, or a good flat block sander

Show us a picture?

As resinhead stated a pic would help, but its probably not flat.

How did you sand your hotcoat? If it wasnt sanded flat, your gloss coat isnt going to go on flat.

You can create low stops and wobble if you sand by hand and arent careful. It helps to use a block to keep it flat.

Soft sanding pads just ride the bumps.

Hard pads make it flatter.