stuck in riot act

[karkalec]

Not sure if this is the right place to ask or not, but I'm playing this great new mod and am at a point where I can't figure out where to go. It's just after you really get outside for the first time where the APC is firing at you. I'm in the building where the water is and have filled the pool up with the valve. The only way forward I can see is swimming through a square hole in the concrete that filling up the water enables you to get near. However, I can't seem to get into the hole. Is this the right way forward or is there another way?:afro:

 

[bbson john]

Try to get the platform below you float upper.

If you suck, read this:

Spoiler

Put the blue barrel underneath the platform in front of, and below, the square hole.