No I think that that is one course you have to do face to face. You can try www.hotcourses.co.uk for distance learning or www.floodlight.co.uk to find out if they do it in any other places close to you.
Are you in London, I know CityLit in central london have various start dates.
I really don't think you can do BSL via distance learning. I went to evening classes and it was still far too difficult. I mean, I could do the signs all right, no problem there, but putting two signs together and trying to make a sentence was so difficult. The syntax of BSL is different to spoken English, there are no guide books around to teach you that (or not in an easily accessible format, they are more reference-type books), and you have no one to practice it with. Our evening class teacher was deaf and used BSL, so we had to try and use BSL with him but a few minutes once a week just wasn't enough. Is there a deaf club near you? You could try and join some of their activities and try and "catch" it from conversation and a few books. You can get some books from Forest Books on-line. Good luck. Why are you intersted in BSL?
yesh it is a visual language and once you get to level 2 in bsl, youre allowed to join the deaf club (coz in level 2 youre learning 'conversations' topic but ive been a few times to the deaf club with my deaf mates before i could even sign and it wasnt much fun as everyone was gabbing in sign! but i got away with it going in the deaf club coz im deaf too) and yes it is correct that you cant right the sign on paper (or even draw the sign)as its impossible so you will have to go to a learning class.