In a recent show they painted a gigantic tanker ship.

The lowered it onto blocks and then cleaned and painted the hull.

I have seen this done before on other TV shows and have always wondered:
how do they clean and paint under the blocks, or do they just not do it?

They never mention moving the ship and repositioning the blocks, which may
not be feasible because the blocks must be in certain positions determined
when the ship was designed and built.

Does anybody know??