Deep down - not actually that deep, the San Diego Bay is not a really deep bay - in the water, there is a wrecked ship, and against a wall of that ship, a portal.
In principle that was the hard part, just finding it, but it's always possible that the inside has more surprises. Nobody's seen inside this one. So they're shelling out to make really sure, because the average length of time it seems to take for each monster to be reported suggests that there are still plausibly hundreds nobody has called in (either because their power is out and their phone is dead or because, well, it's Menagerie, they're harmless till they're not, that's how they get you).
Here is a boat full of scuba tanks and such for Watershed, Kevin Shields, their partners, and Traceless.