+1
In past years I’ve had to rig test boats, so we pull a lot of transducers in a year’s time. Always, always, install a pull cord that you leave in the boat. When you are pulling a new cable (or taking one out) tape/tie another pull cord to it so you will have one in place for the next time you have to pull another cable.
In the DIY snake department: since getting one of the snakes from the maintenance guys stuck in a boat years ago, we started using the bailer wire that is used to bundle up cardboard boxes. Lots cheaper than buying a new snake plus we can get our office lights fixed when they go out!