depends on the temperature, the more you wear, the wetter it gets and the wetter you stay (and heavier) your skin is waterproof, just get a buff for your head and some gloves to keep your didgits from going numb,
i have had a timex ironman for 20 years, works perfectly.
My garmin 305 was bought in 2008 and is still functioning perfectly, although i only use it occasionally these days as i upgraded to a 910, again, no issues, 2 years of use including a lot of water, diving and open water swimming too.
Not the same thing but i once had to live with just 1 eye for 2 weeks after a stone chip off a car hit me in the eye whilst cycling and damaged my eye ball, (never riden without glasses since) and i ran with an eye patch, and i was shocked at how hard it is, i never got used to the lack of depth perception in those 2 weeks, i miss judged curbs and corners and everything like that.
I know it's boring, but have you considered a treadmill just for the time you are recovering?