There's one more thing you could try - in the event that it may be a connection issue between battery and camera, use a gray-lead (ordinary) pencil and 'colour-in' all the contacts on both. It will apply a tiny amount of graphite to the metal contacts, and scrape them clean in the process. I've done that to non-camera contacts (along with a scotch-brite scourer pad in one case), and the problem resolved. It will be a bit tricky doing that in the bottom of the battery compartment of the camera, but should be do-able with patience.

Aha! That's a clue then: No water ingress visible, and a history of misbehaviour pre-incident.

Some aerosol electrical contact cleaner won't hurt then, especially in and around the shutter button assembly. Applied in sufficient quantity, it should penetrate deep enough to flush out any muck that may be playing havoc with electrical contacts inside. And - it evaporates totally, leaving no trace.

If that won't work, repair or replace. KP or K1 coming up!

G'day.

8802a for me - powerful.

A photo finish

But for me, 3 and 1 pip the rest, just.

Two other things worth thinking about:

1. sounds like salt water... Keep an eye on this, for any signs of corrosion or salt deposits (inside with the lens off).
2. depends a little on just where the water may have entered the camera? Clearly it did, and perhaps in more than one location. Have a careful look inside with the lens removed, with a light. Also, have a look at the lens mount at the lens end...

The first one for me - the foreground balances the image well.

G'day Kris! Long time.

Hmm - I AM on a remote island: It's called the Land of Oz!
And yes, lots of interesting bugs (and spiders, and snakes...), so the Tammy 90 Macro would need to be in there. The DFA 15-30 next, and either the FA 50 1.4 or DA 70 Ltd. Can't decide.

Wasn't aware that they made them in K-mount?

But I did hear that the 2018 model will be redesigned using an aspherical lens...