How long is the delay? I have owned several (non-waterproof) digicams and I'm used to about a 1/2-to-1-second or so for focus/aperature/etc in Canon cameras on Auto. In my limited experience Canons tend to be about the quickest camera you can get, but the delay CAN cost you photo opportunities. It really stinks when the seal slides underwater just before you get the photo (grin).
I don't own this specific model yet, though it is on my short list... but...
If this camera works like most other Canons, what you want to do is set up your shot and half-press the button until you hear/feel the mechanics starting to whir away. The camera will let out a "beep" to let you know it's ready for near-instantaneous shooting when you push the button the rest of the way down (I have an older Canon Elph and the shutter time competes favorably with my old Rebel G 35MM SLR). I find this mode is great for capturing breaking waves, etc.
Just be aware that, once the BEEP sounds, the camera will stop focusing or adjusting for light, and when you push the shutter the rest of the way down it will take your photo instantly with whatever settings were established when it beeped. So if you set it up to focus on something 200 feet away, don't expect to be able to turn the camera to the guy 10 feet from you and get a good photo - you have to set up a shot that is pretty similar to the one you end up taking.
Again, I cannot comment on this specific camera, but I imagine the entire Canon line has this feature, and it's darned handy for action photos.
A decent "instant responder" is the Hero Digital, that comes in a waterproof case. I keep one clipped on the deck of my kayak for instant photo opportunities. But it's a fixed-focus, no-viewfinder, no-frills basic camera, and if the case gets wet with saltwater you can easily end up with smudgy pictures, and you'll never know it because you are looking through a separate optical viewfinder. On the upside, it's tiny, light, the batteries (two AAA) last a long time (two NiMH AAAs lasted an entire 3-day weekend of use, about 115 shots), and it's pretty darned rugged and waterproof. As long as you are in bright sunlight, it even takes some pretty nice photos.
But I'm shopping for the D10 because I'm disappointed with most of the photos from the Hero - they were marginally better than the ones from my BlackBerry Curve, but not by a whole lot.... :)