'Proper' Safari and Airflow snorkels are made of plastics that flex a little. I know very little about plastics but I have seen lots of these snorkels whacked against tress and bend, scratch, flex and normally survive. Occassionally they split or crack and the tops and grills usually get knackered quite quickly. Made of fibreglass I think they'd crack too easily unless they are made stupid strong (which they might be, but I doubt it given the thickness they appear in the pics).
I don't use a snorkel, because of the above and because the XJ Safari one doesn't fit around my front flares and the Airflow one doesn't work with ABS because of where the pump is (althogh mine's coming out soon as it's redundant).
I have an intake that comes out of the rear of the bonnet and combined with 6" lift and 33" tyres is plenty high enough for the depth of water I ever go in - if it gets to that height (base of windscreen), other stuff is gonna get shagged.