OK, I will respond to both Bill and Richard here.
Bill: My bow line is 30' in length. (So, when I retrieve the C-Dory onto the trailer, I can walk all the way to my PU, step into the bed, and pull the boat straight onto the trailer from a safe standing place!)
Back to a Canal lock...I hand the bow line to my wife, who is standing at the wall of the cabin, with the stern line already wrapped around another lock line. Then I step back and take her place. Since we are wrapped around two lock lines, one near the front of the boat and another near the stern, I am able to manage/hold the boat pretty well, even if the waters get turbulent.
Richard: I have never gone through a lock single-handed. But I think I could.
One would almost have to grab a lock line from the helm window, and wrap the bow line around it first. Then, I suppose, get back to the cockpit ASAP and grab by hand another lock line, then wrap an at-the-ready stern line behind it.
It is true that there are no locks between Lockport and Rochester; lots of small villages and bridges though. Pretty countryside; leisurely boating.
Since our cottage is nearby, we often put our C-Dory into the Canal at Lockport. There is a good launch (and free parking) on the west side of Lockport at a place called Widewaters. One can also dock overnight there (showers included) for a modest fee; there are picnic tables in a park area alongside the Canal and a hamburger joint across the street.
Lockport has a double lock; it lies immediately east of the launch. Cruise ships start from this spot, because (from the launch) you immediately raise two bridges and then enter the locks, all within less than a mile. Turn around and come back, and you get the whole Canal experience in a few hours!
If you put in at Tonawanda, you will pass through Lockport going west. Beyond that, you will be cruising the "flat part" of the Canal on to Rochester. The cruise through Rochester (where we have a home) is both interesting and beautiful. The Canal passes through a large park: a number of the bridges here (which do not need to be raised) were designed by Olmstead.
On the east side of Rochester, having passed through Lock 32, you come to a delightful little village called Fairport. A nice place to tie up and stay overnight; there are several nice restaurants here. Cruise ships also use Fairport as a starting point, going east through Rochester and return.
ENJOY!