Mike, I don't know the 280; but if it works then that's the answer.
I was just gonna say what Capt JGW said too. This is especially true with Marelon ones.
As far as closing it, I tend to advocate having a checklist and following it (yes; I was a pilot once); and on that list is definitely 'close all seacocks when leaving boat'. Why take the risk of a hose clamp failing? (I have seen
new ones do this!) Also it keeps aquatic creepies from finding a home, leaving shells and clogging up your intake line (before the strainer, which happens). My point about location is that, if it's hard to get to, you'll just omit taking this important safety precaution and then it really doesn't matter, should you have a engine fire-- the boat will now be
assured of going down. Also, if you keep shutting all the others dutifully, you assure yourself the leak won't be any of those; but the law of fatalism says that the one seacock you leave open and 'hope' (my mother's favorite crisis-coping word) won't be a problem will be the one on which the hose fails, because the law of fatalism says you deserved it.
FYI: the law of fatalism is:
If you plan for the best, it'll never happen; if you plan for the worst, it'll never happen.
If you follow my drift; it's really a no-brainer.
BTW as to bilge pumps, read the
Seaworthy book in which Bob Adriance says their exits should always be located as high in the hull as possible, for all sorts of reasons even the most logical people didn't think of. Related to this thread, one reason would be because they do not require seacocks and so can never be accidentally or inappropriately closed, leaving them always open for use (like when you are not on the boat). Gotta give the poor boat a way to save herself!