Anyway to get a jetski before starting the expedition?

[nosaM]

Ray's shop is closed before starting the expedition, Maybe I could raid the cans port and see if I could lure the guy on the jetski somehow. I just raided the cans port pretty easy battle with an smg and mk5 grenades.

[Tamior]

You can still lockpick your way to some of Ray's jetskies.
Once you drive it away, you should be fine afaik (assuming you never shown up on it in Core City).

[cypherusuh]

It would be much easier to just start expedition. For the first raid event, just buy as many bear traps as you can around Underrail, and lay them all, and i mean quite literally, on every single tile on that map. If you have trap skills or have high enough Mechanics, lay some mines with the help of Jackknife and trapper belt

[ciox]

It's not that hard to get the Skimmer from Ray's shop, you just need to make a detour so nobody at the docks sees you riding that jetski.
Once you've left the map without triggering anyone's hostilities, you can come back later still riding that jetski and be fine.