[Marhkimov]

Question 1: download the newest edition of RUb (1.43, I believe...) and you won't have to worry, because underwater you won't be able to see a thing. I guess that's the way it should be?

Question 2: experience is all you need. After a while, you won't even need to use your recognition manual for such simple proceedures. Once in a while, you'll have to look up a draft depth or something obscure like that, but you'll know the diff between a C2 and a C3 like the back of your hand...