I forgot to pump out the water using the provided hand pump on my 496 last night. It got down to 26 degrees from 3am to 7am.
I know the block has anti freeze in it- no worries.

What other damage could occcur. Sea Pump, Heat Exchanger ect.???

I have also heard that it needs to be well below freezing for 12 hours or more, like a weekend that was below freezing the whole entire time.

Any thoughts?
R- Seattle, WA

26* for 4 hours will not freeze water. It will be fine.

Not long enough time, you should be fine. If you like stick a cup of water outside the next time it gets cold and see how long it takes to freeze.