Thank you Miss K. for the very generous compliments.
Those Packet Boats that I'm so fond of photographing are indeed rentals. I did a quick 'Google'...
Erie Canal Packet Boat Rental, and got these three quick hits.
http://www.houseboating.org/ERIECANAL/overview.cfm
http://www.westernny.com/canalling.html
http://www.westernny.com/midlakes.html
I'm sure there are many more rental places out there. I also see a lot of privately owned boats on the canal. I believe the Erie Canal is linked to the Inland Waterway that runs down along the East Coast. The canal also offers access to the Great lakes from the Inland Waterway.
With enough research you might be able to time your vacation to include one or more of the 'Canal Days' type celebrations that occur in many of the small towns on the canal during the Summer.
The Erie Canal gets a lot of pleasure boat traffic but is by no means crowded. Many of the canal communities are just starting to realize the potential that the waterway offers. The towpath along the canal is quite popular with cyclists also. I've read ride reports of bicylists from Europe who took cycling vacations along the Erie Canal.
This event might be of interest to you also
http://www.ptny.org/canaltour/
It's been on my 'Bucket List' for quite a while. Maybe someday........
I hope this has been helpful to you.