If you remove your rudder frequently, you might pay attention to what method you use for ensuring that the pintles don't slide out of the gudgeons. Some methods are very secure, but fiddly to put in, especially on the water. I rarely have to contend with chop, so I found in my case, these two are sufficient (and can be disengaged with one hand while lifting the rudder with the other).
If you look closely you will see an L shaped little bracket that's screwed in not so tight that it can't swing down by gravity. That stops the rudder from rising. As backup, there's the bent strip of stainless that's barely visible on the left. It angles away from the rudder at 30 degrees and rests on the tip of the pintle. When raising the rudder, it would wedge itself under the gudgeon.
When installing, the L bracket is easily pushed away sideways and the strip doesn't resist going down, and best of all, unlike some other systems, you can't forget to engage them.
(That said, for longer cruises in rough conditions, a cotter pin through the tip of the pintle is most secure).