you know when you have one of those lightbulb moments? yeah - just had one.
We flew on 737-300's, and there was never any special mention in any 73 drill in regards to the possible unsuitability of doors 3. Of course there's the standard "assess conditions" across all fleets, but nothing saying that the thing sits ar$e-heavy and to replace cabin flats with gum boots!
And ALL of our flying includes signifigant over-water routes!
Makes total sense, and I feel a wee bit dopey only realising this now!