Yes you pass on the right however this is not always possible for some large narrow boats due to bends, depth of water, overhanging trees etc. 4 mph is the speed limit but it is the amount of wash you create that erodes the bank and spills the champers on moored boats neither of which will win you many friends. You also need to be wary of shallow water where banks have been eroded and underwater obstacles supermarket trolleys etc. Locks are dangerous and the top gate has a sill upon which some boats get trapped the other end then continues to descend, the boat then becomes trapped on the sill refilling the lock can cause the boat to take on water and then sink ! this picture :http://www.mailonsunday.co.uk/news/a...anal-lock.html
shows a narrowboat trapped by moving brickwork ( not the sill) similar effect though also you may find this pdf helpful http://www.waterscape.com/media/documents/1784.pdf
I would be very wary about using canal locks in a sib if you share with a narrow boat the movement of the water sucks the narrow boat backwards & Forwards and you could get crushed.
You also need a licence unless you are going to "claim" it is a tender for one of the boats you have just passed