BillyK, I would definitely go horizontal too. I have this saved to think about the install and beefing up the anchor locker lid if I decided to put a windless on my Catalina 28 (and he did ask about vertical).why go vertical rather than the horizontal install the way the anchor locker is designed to be?
The problem with putting it at the rear, is that the chain/rode would have to cross the hatch on the way to the windlass, making it impossible to open the hatch and clear any jam while recovering the anchor. I suppose I could keep the hatch open for dropping and recovery activities. Additionally, I have no interior access to the anchor locker, and a smooth gelcoat headliner in the V-berth. Below is a picture of someone else's H31 V-berth to show the underside of the anchor locker.@pateco Chip the chain strips going forward. It makes a 180 around the windlass gypsy. So you might want to build it into the locker on back side not the front. I would look at a few installs in your marina to get an idea what others have done.
I understand that if you can install the motor in a dry space you will have less corrosion over the years. I am looking at positioning my windlass with the motor over the V berth behind the hatch to the anchor locker.
The chain drop will be in the anchor locker in front of the bulkhead into the anchor locker.