As far as is safe
not exactly sure, but I'd assume that it's exactly the same as driving behind a tractor, keep your distance.
you should stay at least 100yds away
7 car behind
It can all depend on a number of things, including where you live, what is being towed, and what your insurance will cover. You should count on at least around $100. It will also depend on how far you need your vehicle to be towed.
you should avoid throwing the anchor as far away from the boat as possible and back up
You shouldn't walk behind horses you're not familiar with, but if you have to, you should rub your hand across their body as you walk behind them (so they know you're there). If you don't want to walk close to them, you should walk really far behind them, so that if they do kick, you're too far away to reach.
Throwing the anchor as far away from the boat as possible and backing up
Throwing the anchor as far away from the boat as possible and backing up.
Throwing the anchor as far away from the boat as possible and backing up
Throwing the anchor as far away from the boat as possible and backing up
If you can bail it out. If you have a working radio, call for help. Finally, if you can stay with and preferably on the boat as the boat will make a bigger target for rescuers to see.