Quiz: How many ferries across the Thames are there in London?

So now we've defined how much of the Thames is in London its time for another quiz: how many ferries are there across the Thames in London?

But what do we mean by ferry? In this case I'm going with boats that take members of the general public as passengers between two points approximately on opposite sides of the river Thames (e.g. with line of sight between them).

So the Thames Clippers do not count if they go up and down the river e.g. from Embankment Pier down to Greenwich.

Then finally what time period are we talking about? In the past there were lots of ferries and this is meant to be about ferries in London now. But some ferries don't run all the time and at least one was recently suspended.

The final definition is then the time frame:

• The ferry must have run for at least one day in the last year, taking members of the general public directly across the river Thames at some point between the London Stones.

So what do you think? How many have run over the last year?

And how many of them have you been on?