I noticed that the Kino Bay is only available in one body style and that is "keychain". What I can't tell from the pix on FR of some of the other "keychain" Peak lights is whether or not the light is waterproof with the keychain attachment unscrewed. It looks as though there is a set screw inside, but I'd like to know for sure.
Additionally the Kino on FR looks a little different than the one on Peak's site,
and I'm wondering if it's changed?
I doubt it would be waterproof with the keychain attachment unscrewed. On keychain models, beneath the attachment screw there is the removable negative battery contact, which does not have its own o-ring, but relies on the o-ring of the attachment to seal the body.
However, if you want to use the light without the keychain attachment (for reduced length or to have it tailstand) you can get a *flat* screw replacement (including an o-ring) to use instead of the keychain attachment. These parts aren't listed on the Kino Bay accessories page, but e.g. as a Mediterranean accessory, and should fit (at least on all my Peak lights, these attachments are interchangeable; I don't own a Kino Bay myself, though).