Maybe @Shearwater could add the splash screen as one of the info screens that appear when you roll through the screens. - Just a thought.Yeah, the only thing worse (to me) would be if a cave diver took it, knew how to turn it on, and ignored my splash screen with email and phone number.
My detective gene is prompting many questions. Because I don't know the area I have to ask if your lodging is frequently/heavily used by divers. The second, which I'm sure the police have done, is to secure a list of all guests at the time and check if they were divers. I truly wish I were local so I could have sleuthed this at the time.
If a diver took it, there is a likelihood that your splash screen now has their name and phone number. This loss REALLY make me sick to my stomach. It's sort of like if I ever catch the person who stole my competition pistol. There may not be enough of them left to arrest. Thieves and liars have a special place in Hades.
Good luck. I (sort of) feel your pain and I'm in your corner if you need me.
Cheers -