The main thing to know about this run is where to take out, or accidentally running into Daisy Lake Canyon section of the Cheakamus could be more of an adventure than you hoped for!
The takeout is on a left bend of the river just before a rapid with a beach on the left which can be used if you miss the preferred take-out. There is some flagging tape at the first eddy on the left to indicate where to take out. There is often someone camping near the take out, and there's a short walk up some steps back to the vehicles. It's not super obvious so go check it out before getting on if it's your first time. The put-on is the take-out for the main Callaghan at the Cal-Cheak Rec Site, please park on your left near the trash bins as the campground host likes to keep the side nearer the river clear for RVs. He's been there a few years and doesn't seem to mind people skirting his site to walk to the river to check the gauge, but please put on a bit further downstream.
The Cal-Cheak is a fun section with some nice surf waves at higher flows. You're starting on the Callaghan below the famous main section, either above the bridge for more waves or just below, then shortly after the campground the Cheakamus joins from the left. It is possible to also start from the Cal-Cheak North Rec Site in which case you start on the Cheakamus River at the take-out for the Balls Section, this is less paddled and sometimes has wood.
There is also a small gravel yard on the North side of Highway 99 which has a put-on further up the Callaghan and there are sometimes a couple of waves there worth a play.
There's only 3 real rapids of note. The weir drop near the start, Testicle Rock and the ledge wave/hole, the rest of the river is read and run boulder garden.
This is a fun river for intermediate paddlers, lots of good eddies and waves to surf! The river goes at almost all river levels, but becomes more consequential at high water due to the limited time to rescue from the last rapid to the takeout and wood is a persistent issue. The River has the Cheakamus Flow and Callaghan Flows so depending on rain or melt one can be much higher than the other!
The weir drop is long and runs diagonally across the river from left to right, stick to the outside of the bend at first then aim for somewhere near the middle-right where a small shelf sticks out. There are various options, and it normally feels a little shallow heading into it. River right always goes too.
Testicle Rock (Also known as C*ck and Balls) is two large boulders that seems to eternally have a large piece of old growth wood shafter down the middle. Wood often collects around here too creating nasty sivs. Sticking left you can normally stop in an eddy and boat-scout the best way down the left below the rocks.
A few more waves and one more significant rapid and you're very quickly at the end of this river. Again the take out is not obvious, I've overshot it before and had to paddle to the eddy on the beach instead.
Downstream is Daisy Lake Canyon, in an emergency the first part of this section is mostly read and run class IV+ and it is possible to get back up, but it would be a lot of effort. Gear lost on this run is not worth chasing down there and will often end up in Daisy Lake.