To be honest I reckon the camera's weather sealing has done you proud as you are still able to take photos with the camera. It doesn't sound as if it is totally bricked. I'm wondering if in your accident the rear screen got bumped somehow, it might be just a broken wire or dislodged connector but how could we know? Can you post a photo of the camera, showing in particular the backscreen? It may help, it may not!
As outsiders it sounds for sure the back screen could be replaced if need be but we're not Pentax technicians and we've not seen the camera so all the replies are really stabs in the dark. It could be you're lucky only the back screen has stopped functioning. I'd still look to make a claim on the insurance for it if you can, though if there's no obvious physical damage it might just need time to dry out.

I expect there's one sitting in a dealer's clear out bin somewhere, unloved, unwanted. But your guess is as good as mine as to where.
Tamron actually have a UK operation at: http://www.tamron.eu/uk/ so maybe give them a call or email?

To me it's saying it is not an underwater camera like the Optio WG's but can cope with rain and spraywater (I know I'm not David!) Have you checked your household insurance yet or put it in the airing cupboard to start drying out?
It's a bit like waterproof watches. Once they've been opened to change a battery they're not usually waterproof any more.
Given you mention your watch getting wet too, did you fall in? If so, could you have knocked the camera on something somehow? You haven't really given any details. If so, perhaps there's physical damage. We don't know!
You can't really blame Pentax for your mistake though given sight of some of those videos of Pentax's being washed it does seem you've been unlucky. Given the camera still basically works I can't see why its dangly screen cannot be replaced if that's all that's wrong. If it isn't otherwise damaged, give it time and see if it recovers.
There's a nearly new second hand one here for £1400: https://www.lcegroup.co.uk/Used/Pentax-K-1-Body-Only-Just-100-actuations_165522....

Seems there is but not in the UK.

http://www.ebay.co.uk/itm/112mm-112-Screw-in-Metal-Front-Lens-Cap-NEW-Sonia-Brand-/151521306202?hash=item23475fa65a:g:~SYAAOSwHnFV3ext

http://www.camerahouse.com.au/products/Caps-1/Tamron-112mm-Front-Lens-Cap.aspx

http://petapixel.com/2016/03/21/testing-pentax-k-1-mud-shower/
Try opening all its hatches and putting it in a warm airing cupboard. Fingers crossed, you never know it might clear it.
Suspicious suggestion that you give the dealer it unless a very generous p/x offered.
Was it sea water? That might cause issues - corrosion etc.
As suggested, check your household insurance. As its over £1500 I've included mine on the insurance as a named item (at a slight extra cost.)

+1

Carry on here if you wish. My query has been resolved so thanks to all for the help.

Did you realise he wrote that four years ago?

As far as I know DSLR sensors are normally covered by a mechanical shutter similar to film SLRs so shouldn't easily get grot on them! No more than a film would.
I suppose because the sensor is more exposed when using live view there is more chance of it picking up foreign objects that happen to have ingressed into the camera during a lens change. I've never experienced a problem so far, even with my K-01 or 'Q' which are live view only.
If it is anticipated using the camera out to sea (say) in bad conditions or on a rainy day probably best to stick to a WR zoom and not change it unnecessarily.

Pleased your K30 is sorted and happier now!