I've seen this before:
the forcola, remo, and dock-lines from a gondola - all wrapped together.
It's a great way to keep them together, and while a forcola and remo in Southern California are quite unique, in a squero like San Trovaso, I can see the need to keep them together.
Each gondolier has his own rowing gear.
Imagine how easily a forcola could get lost in a place like San Trovaso or one of the other squeri.
Rowing clubs often do similar things to keep the rowing gear for each boat together.
If you have a sharp eye, you might be able to spot the lucky horseshoe in the shot.