Hull Paint Project, Part 5

Charlotte Harbor Boat Storage

We are in the process of sanding away the botched paint job.  It is very difficult because this paint is very very hard.  It will take 5 days power sanding to finish.

Here is a picture showing the bad job.  I spray painted black over the top, then I partially sanded it to make the imperfections visible.

I have three theories of what went wrong, and no good way to verify which it is.

1. We did not spread the paint thin enough.   Countering that, the can says coverage 100 square feet.  I spread it 150 square feet. On the recommendation of Jamestown distributors, I bought 6 750 ml cans of paint to complete two coats.  We used only 2 cans on the first coat not 3.  Still it seems too thick.
2. We moved too fast.  We did the whole 300 square feet in one 4 hour period, 7-11AM when the temperatures were within the allowable range.  That means a lot of moving ladders, and little time to revisit painted places and tip and re-tip 10, 20, 30, 40 minutes later.
3. When tipping with the brush, we might have been too generous with paint thinner on the brush.  It would be running dripping thinner, not paint that ruined the job.

Any thoughts?