I use a Canan EOS 400D and use it quite a bit out on the sea. Im anal about trying to keep it completely clear of salt spray, rain etc. Can I get something to cover the camera while also allowing me to use it as normal
Check Ewa-Marine (http://www.ewa-marine.com). They make waterproof housings to allow normal SLRs be used when diving so they probably have something you can use sailing.
Think I saw someone else recommend a shower cap or plastic bag, does the job of keeping your camera body dry, and its considrably cheaper than a dive housing.
As for the lens, if its someways covered upto the glass, all you will have to worry about will be wiping sea spray of once in a while. A pack of baby wipes and a lint free cloth (like you’d get with a pair of glass’) does the job.
I use Kata rain covers for my workshops and find them to be excellent. They are just rain covers, but without going for a full-on housing there’s not much you can do to completely protect the camera from salt water.
The specialist housings are really expensive and unless you are planning on diving they are not really worth it. You are limited on the lenses you can use and if you change the camera to a different model, the housing is useless.
I have the KATA kit that peter reccomends and would add my reccomendation to that.