George, classic shot though its tonally a little flat. You mention that you are new to the 10d, be aware that you are probably going to have to get used to running everyhting it outputs through PS to get everything perfect. Don't look at it as a deficiency of the camera but rather an opportunity to get into developing! PS is your digital dark room. Alternatively the Canon software is really good. For hurriedly prepared press stuff that is normally my first port of call and it can sort out most things fast and efficiently.
I took the liberty of having a five minute twiddle in photoshop and tweaked the contrast, levels, burnt the sky and then dodged some of the darker areas of the baot to balance it out. Please be aware that the file size and the time spent make my attachment far from a masterpiece but hopefully it gives you a rough idea of what I mean.
Two further comments would be the cropping of the stern of the (very fine) yacht (its not yours is it?!) Given the viewfinder crops anyway were you going for a tighter compostion? With a shot like this you can go either way, show the subject full frame or really be quite aggressive with your crop. If in doubt pull out! you can always crop down later.
I'd also question the desaturation of the image, I recon this would be even nicer in full colour with the saturation pushed up a little, levels sorted and a bit more contrast.
You asked about the Sigma 17-35mm. Its a lovely lens if not the most portable. It really is very heavy (but very robust) and pretty fat. Having said that, when it has the scalloped hood attached I almost could be mistaken for a proper photographer :-).
Over in the states you guys are lucky, new te lens costs £400, though I picked mine up nearly new for half that, probably what you'd pay in dollar equivalent. Its worth shopping around for a bargain. Overall its highly recommended, the focal length equates to roughly 28mm - 50mm on the 10D, so it means you get the bottom end of all those cheapy USM zooms back. Having said that at 17mm the aspherical lens does give a degree of distortion which I make maximum use of for action photography and I prefer it to a fish eye (Okay I can't afford a fish eye!).
If buying second hand make sure you look for a graunchy noice when you zoom and for dust inside the lens. Also, some earlier ones need to be chipped by sigma to work with the 10D (if you get one of these it will be stuck on f2.8 whilst everything else works) so best not buy it mail order. Also budget for a UV filter, it takes and 82mm which is a whole bunch more than the 58mm you are probably used to buying.
Buy one, stick it in your bag and you'll be a happy snapper