I have been shooting with various EOS 1 series for years including shooting soccer in some pretty heavy rain and those bodies have been fine. I try to use weather protection when possible but the gear has gotten quite a bit of rain on multiple occasions without any issues. But the weather sealing on them only applies with certain lenses mounted including most of the telephoto L series which have a proper mating gasket to weatherproof the lens to body interface AND it also assumes the camera is in good condition. Seals can deteriorate with time and use.
There is nothing worse than salt water for electronics and I definitely wouldn't want an ocean splash on any of my gear. The initial problem is the high electrical conductivity of salt water which can create immediate permanent electrical damage and if a splash occurs don't just turn the camera off but also pull out the battery immediately. The longer term issue is the corrosion that occurs including attacking the seals around the leads of electrical components such as electroytic caps which will release their own corrosive chemical stew if the seals are breached.
I don't think I would have the nerve to do this to one of my DSLR bodies but the standard electronic treatment for an item that gets a heavy dose of salt water is to do an immediate very thorough fresh water flush ending with a complete rinse using distilled water. When done immediately, electronic gear is often saved by this rather drastic treatment but I wouldn't bet my life or career on any piece of electronic gear that has had serious salt water exposure. With just a splash, invert the camera so that water won't pool at the control seals and then wipe clean immediately.
Electronics can sometimes survive surprising abuse. When my 2008 Cadillac CTS was brand new I did an initial 1,000 mile oil change and when I went to put my clothes in the dryer I found my freshly washed key fob. That was the first car I owed with keyless ignition and it was a somewhat involved fob. I removed the battery, did a thorough flush with WD-40 (the WD originally stood for water displacer), and then dried it out. It got a new battery and the extremely clean fob worked perfectly although for several months I carried both key fobs with me just in case. Six years later I traded the car in on a 2014 ATS and the fob was fine so it survived machine washing with Tide detergent but that doesn't come close to what salt water can do.
A related issue is when moisture and particularly salt residue builds up on a camera body which is later brought inside from a hot environment and allowed to cool. As the body cools, unless there are other relief vents built into the body it may suck air past the seals as the interior cools and interior air pressure drops. When this happens, any moisture and corrosive products around the seals will be drawn into the camera body. Never quickly cool a wet camera body, dry the exterior as well as possible and preferably leave it in a warm but sheltered environment to finish drying as the temperature and pressure equalizes. Taking a hot camera into a cool cave can also cause this issue.
Rice is a decent desiccant but i keep several packs of silica gel around for use primarily with electronic projects but for other emergencies also. It is readily available and works better than rice. Silica gel can be carefully baked at very low temperature to drive the moisture out so that it can be reused indefinitely. Silica gel cartridges used for mil spec gear are typically of the color changing type and it turns pink when it becomes saturated turning back to blue when ready for use. Some consumer silica gel is also color changing but if you only have the regular non-color changing type you can still heat the loose "raw" pellets at up to 300 degrees but don't bake the enclosed packets at over 230 degrees. When traveling I keep a couple of large packs of silica gel in sealed baggies in my camera bag just in case. I felt it is safer to use labeled silica gel packages when traveling but a couple of decades ago when entering Cuba I was asked to allow them to cut them open while clearing customs so it can lead to questions however rice would probably be an even bigger issue because you might run into agricultural inspection issues when crossing some borders as control of agricultural pests and diseases are of prime importance.
Rodger
EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video
