: I carry my spare euro paddle INSIDE my stern hatch. There are those
: who will tell you that it's not as safe as having it on deck,
: but get real.

OK, the paddle in your hand is more likely to be snatched away than the paddle flat to your deck.
One of the things we practice on our sea safety days is throwing away a paddle, capsizing,
leaning back, grabbing one half of the split paddle off the aft deck, and doing a reverse screw
roll to come up. You are now upright, in your boat with half a paddle. Not good, but a whole
lot better than upside down with no paddle...

It depends what kind of paddling you do whether this sort of thing is an important scenario,
but when paddling in among rocks and swell, it's unlikely that anyone else is going to get
to you quickly and risk opening a hatch to get you a spare paddle... Even if you wet exit
and want a paddle to do reentry and roll, you are unlikely to be able to get a paddle out
of a hatch in a situation which has just capsized you without your main paddle.

Sometimes I want to swap paddles because I'm tired and/or injured and I need to
change to a smaller blade. It's never happened anywhere where I'd risk opening a
hatch, even rafted up.

If the sort of paddling you do is where the most likely cause of a lost paddle is carelessness
in calm conditions, a paddle inside a hatch is probably fine !

Andy