From Unca $crooge:

Usually I can understand the 9CL strip. It’s pretty formalistic, with a gag built around a super-hot, oversexed bimbo who is somehow coupled with a worshiping wimp who collapses into a catatonic state whenever in close proximity to said sexy partner. There are a half-dozen of these couples and while Brooke usually focuses on Super-Bimbo (Edda) and her identical daughters (Lolly and Polly), he occasionally switches things up and brings in one of the second banana couples. This week Brooke has turned the strip over to animal doc Fleurrie and her assistant / husband Sven who for the past three days have been rolling around among the cow chips while poor cow patient, Victoria (who can’t seem to swallow her grass), is forced to watch. Today, though, the scene shifts to the local lake where Fleurrie takes a dip into the frigid New England waters. Sure, it is the standard setup to have one of the hot women in a bathing suit but is there a joke here?

All I can come up with is that Sven grabbed her feet and pulled her under, but that sure isn’t obvious.