Based on a story full of familiar Simenon themes (troubled souls with a murky past and the milieu of the wealthy contrasting with that of the water-based poor) this episode gamely tries to use the location budget to set a scene of canal-side life into which tragedy comes by boat but suffers yet again from its inability to convincingly portray the way in which the different social strata actually differ.
On top of this though, is a worse problem of fiddling with the denouement to get an action-packed ending but then doing nothing to fix the effects that this has on the murderer's motive and the manner in which the murderer responds after the murder, neither of which makes sense.
Many poor episodes in this series could have been saved by some intelligent departures from the original novels and yet when sticking to the original is the best option, the creatives go out of their way to make a mess of it.