Chatfield gravel pond OWS question

I know that several groups offer their members the opportunity to swim at the Chatfield gravel pond in the summer, but it's not clear to me whether all of these are ultimately the same exact times; i.e. those offered by COMSA.

In other words, are there any groups who offer swim times other than the MW afternoon and Saturday morning sessions (at least I think that's what the times are) at Chatfield? I'm trying to figure out my summer schedule and whether I can commit to long runs very early on Saturday mornings, which I'd rather not do if it means I can never go to the gravel pond (since I can't make it down there during the week before 6:30 pm).

Thanks!

--Stacy