Exactly which why I said a 16 year old boy carrying a Bo on public transport in one of our towns or cities would be perceived as being odd, to say the least. In some places being stopped by the police would be the least of his problems. In rural areas like mine plenty of people carry walking sticks/walking poles/crooks/thumb sticks etc and we are well able to differentiate between those and a Bo carried by a teenager. One attracts no attention the other can cause alarm. The days of carrying quarterstaffs a la Robin Hood are long gone, ( a lot of the Kevin Costner Robin Hood film was filmed local to me so we saw a lot of 'staff' posing with the cast)
Thought you might like these, they are expensive though.
Shepherds Crooks at The Stick & Cane Shop
There are literally only a handful of martial arts suppliers in the UK, I guess they could all know each other so perhaps they have decided together or as they say great minds think alike. All I know is that they all have it on their websites.