Canal boat statistics - help needed

For the last few weeks I've been counting the number of boats on the waterways on the edge of Hackney.  The stretches of water I looked at were between Markfield Recreation Ground (border of Tottenham and Hackney) down to Wenlock Basin (on the border of Hackney and Islington).

When I started I misinterpreted where the canals of Hackney ended and had to add some extra areas hence the sudden rise in the number of 'layers' at the top of the chart in the run-up to Christmas. 

Otherwise each layer represents the number of boats on a particular stretch of canal. These territories are stretches of water between landmarks, usually bridges, where small communities of boats have grown and then dispersed. 

(This also seemed to be happening on the canal bank too.  This picture shows what looked like the rise of a tiny shanty town growing on the fringes of Hackney Marshes - on the bank opposite the garbage truck area. It was there every week but had disappeared on the last trip, Saturday 28 January.)

As the chart shows, over the last few weeks the number of boats in and around Hackney peaked above 300 during Christmas and New Year. I'm hoping it will be interesting to watch how these boats move about particularly as the Olympics come and go. (Although a lot of the canal I'm looking at is not in Hackney at all but in Tower Hamlets and Walthamstow too.) 

Help needed

The chart has too much information on it to be able to show what area each layer represents and only some of them are listed  down the right hand margin but not all.  So I'm working on how to get all the information into a useable format that I can update. If anyone has any tips or advice it would be greatly appreciated. 

I'm trying to work out how to use Google fusion tables, you can look at the data and copy it etc here and I've also made the data public on something called Buzzdata (I'll make this link live when I've worked out how to use Buzzdata!). 

It's all new to me so any advice on how to collect data, whether this data is worth collecting, and how to present it would be very helpful particularly if anyone has any good examples I could copy.