contactable yes, if poss but not obligated/expected to drop everything/stay sober or in range, it was this expectation that caused the controversy on this thread.
If I'm in the pool or a lake/river/body of water I'm out of contact. If it's for a day, usually DS will be with someone, a friend etc, otherwise if it's just training he's fine on his own, but he is older.
Sure there are whole herds of MNers on AIBU that will froth and rant that everyone no matter the circumstances needs to 'suck it up' at all times. it beggars belief here at times, but I do think that there are far too many who doubt their own ability to function, and that for many of us, there is no option and it really isn't as big a deal as they think it is.
The saddest thing I ever heard was some yummy braying to a child that 'Daddy's money pays for all the boring things like bills, Mummy's money pays for all the fun stuff'
What kind of message is that to my DS? that His role is to work like a dog and not get any of the fun? that mummy's job isn't important? that women working isn't important?
It really upset me at the time, because without his Mummy's money, DS and Mummy would be living in a cardboard BOX!! Even DS was horrified and just looked at me 
Being biologically different doesn't reduce the ability to care, no, but often a woman sees the child as HERS more than they belong to their father.
That said I know that I would say that DS is mine, and mine alone. His dad has done sweet FA and I don't trust him because he can't put anyone except himself first. I've given him chances, he failed every single time.
Society needs a huge overhaul, for sure.