I think zinc oxide is actually the safest sunblock there is, from what I've read. There have even been studies on nano-particles of zinc oxide that found (surprisingly to all involved) that it was not absorbed through the skin.
My favorite is eco:logical. Larger particle zinc oxide only, unscented, doesn't go rancid easily, doesn't separate quite as readily as some other brands, doesn't leave a blue sheen, stays on through sweat, doesn't take a lot, works fine, not too bad on my EXTREMELY sensitive skin. I'm a convert from Badger - which goes on very blue, contains heavier, greasier oils, separates easily, and contains sensitizing lavender oil (besides men don't necessarily like the fragrance).
I will not use nanoparticles of titanium dioxide (it actually undergoes a reaction with sunlight that creates cancer-causing free radicals), and most chemical sunblocks aren't safe either for sea life or for human life.
Still, if I can cover with fabrics I'd rather do that than put anything on my skin that will attract dirt and keep me from sweating. Sunblock goes on nose and cheekbones to keep them the same color as the rest of my face; earlobes and neck to cover what would just get rubbed off anyway and/or is outside the range of hat or visor; and that's it. Something else on my lips usually, though I've used the eco:logical there too in a pinch. Occasionally, if I'm out on a rare long day in sandals, the tops of my feet will get some too. I love the function of my de Soto arm coolers, but the fit is so weird that I just ordered a pair of the Zoot arm coolers for comparison. I'll let you know...
ETA: The eco:logical sunblock is widely available where I am, but I just checked their website to see, and West Marine carries it, so you should be able to get it at retail no matter where you are as long as there's a lake, river or ocean nearby. If not, there's always ordering it through your local natural food store if they don't already carry it, or the intertubes.