surf key

Hi all I need a way to lock my van and be able to take the key kitesurfing with me. I am currently using a waterproof pouch but was intending to just get a passive key cut so I could leave the active key in the van. However the local Timpsons to.d me this was not possible does anyone have a way...

when I bought my van I was given 3 keys. 2 of them are the remote key fobs that work as expected. I also received a ‘normal’ key. Non folding no big fob. What is the point of this key? If I open the door with this key the alarm goes off.

Does anybody know if: On my T5.1 I am able to lock the vehicle manually using an unchipped key and then a couple of hours later unlock the vehicle without setting off the alarm. That allows me to take the unchipped key sailing without the risk of getting the electronics in the standard key...

Looking through VCDS it looks like it's possible to set it to disable the alarm on unlocking of the door with the key. Presumably this means that I could use a key blade only, with no chip, to unlock the door and then retrieve the proper key from inside a locked safe? It's not something I'd want...

I don't surf, old joints and the coordination of a 3 legged hippo prevent that, but I do swim and snorkel in the sea, along with fishing in places I very often get soaked. In my old T5 I could lock the van without setting my alarm but I can't in the T6, so what's the best solution you guys use...