I’d have walked the tracks if I was alone or with some mates and no phone, sensible thing would be probably to wave down a train driver.
Looking at the map you’re a 1km walk along from a 20/30m swim. This time of year would probably be doable, but would be pretty cold, I can just about handle 15C water jumping in and out for 10 minutes to get used to it, then I could handle it long enough for a 20/30m swim, but not much more..
But this time of year, we’ve already lost 3C on that, sea temps around glasgow are sitting at 12C just now, so probably about 11C up there. That’s a massive difference tbh.
an unexperienced swimmer, ie. me, could easily get into bother there, even over a short distance. Trying a 3/400 swim, unless you are a cold water swimmer and used to it, would probably just be stupid. Not to mention no wet suits, I’m guessing.
loch temps can be colder and warmer than the sea mind you, just using the sea temp numbers as that’s all that’s ever measured online as far as I know.