The figure shows the features produced by the optic mount at the top of the periscope before maintenance (red) and 3 hours after recovery from maintenance (blue).  The amplitude seems reduced by nearly 10, but lets see how it ages. I used a watercolor paint brush to apply 5 minute epoxy to the base of the U-200 mount at the top of the periscope. I used one brush load. I was only able to paint the epoxy at the left and right sides of the mount because the middle was over a cutout in the base plate. After the epoxy was mostly cured, I adjusted weights on the periscope and optic, minimizing the peaks in IMC_F by placing them in valleys between periscope resonances.

Robert, Rick