First time to winterize!

I am located in Ocean City Nj. This will ba my first attempt at winterizing both crusaders, and all other water systems (ac, generator, head, water systems). Any pointers wouls be helpfull!.
Thanks

Yes! Air will not freeze expand and cause expansion damage!
I'd suggest to always follow your OEM manual for your engine/exhaust winterizing procedure. The manual should show you where all low point drains are.
Be sure to probe these drains with a wire or ___ when the plugs are removed.

No matter how appealing pouring anti-freeze into systems for freeze protection may seem to be......, the risk of dilution always exists.
You must know exactly what you are doing if you choose to use this procedure.
If you do purge your engine and exhaust systems with anti-freeze, simply drain it afterwards.

If your system allows, I'd also remove the sea water pump impellers for this duration, and place them on the shelf.
You can extend the life of one, if it is not left in the pump housing for the lay-up duration.
Your call on that!

As for O/B potable water systems, the RV type anti-freeze works well, again, if it does not become diluted.
Do a search on marine WH By-Pass valving if you want an easy method for your O/B water system.

Remember..... Air Won't Freeze and Expand!

.