Once the engine is warm from running on this system and thermostats open, then you can run some environmentally safe antifreeze through it and she's ready for cold weather. When you get a nice day, hook up and head for the water!
This year I'm paying more attention to the discharge hose as hooked to the tailpipes. I am using a longer hose system, more securely hooked with clamps, discharging into a single bucket. In addition, that single bucket has a recirc hose attached so I can just run the motor and get things nice and hot without having to haul buckets of warm antifreeze up to that container you saw in the photos last year. This small investment in time makes up for it quickly in convenience, and now I'm apt to use the boat more often in cooler weather too.
Paul