"dogs off chains".

In sailing circles, when the wind is very strong it is sometimes said to be blowing "dogs off chains". Possibly this means that it is strong enough to, literally, pull a dog from its tether chain, but is there another explanation or origin for this phrase?

"Blowing Dogs off Chains" (an Aussie/Kiwi expression for a windy day)...."

Or: As predicted, today (Tuesday) in AKL [Auckland] it has been raining cats and dogs, and "blowing dogs off chains."

Question 2: Its blowing dogs off chains, I am approaching the lay line down wind [i.e., downwind] at warp speed, what is the top tip for surviving the gybe? (From a boating site.)

I don't know why this particular metaphor. It's used mostly as "blowing dogs off chains," describing strong winds over open water, mostly by Antipodean sailors. A wind strong enough to blow a dog off his chain is some wind!
SS