WOW, I'm glad you're ok. Yeah there are some boats with 2 bilge plugs and that's very confusing. I'm sure you'll never forget again after that experience, but I always lift up the engine cover and check the bilge for leaks of any kind, launching any boat for any reason. You never know!

Sometimes people will put the plug(s) in a little plastic bag, then stick the key right through the bag so you really can't miss it.

Keep an eye on your oil, just to be sure you didn't get water up too high. Did the starter get wet?

Oh yeah and I'm glad it didn't overheat - yay! That's a sweet automotive hose you had there.