When I drowned my bike a while back I wondered how larger (not that large) bits of organic matter got in the motor as they wouldn't have fitted through the air filter and the filter was almost 100% clean on the inside despite having a layer of mud about 10mm thick on the outside. The exhaust didn't go under, so it didn't go up there.
Short version - it was a partial drowning, bike ran fine for the rest of the day - about 60-80klm or something. Get home to wash it and find an airbox half full of water and mud - not my finest moment.
A mate wondered the other day, when we we're laughing about how well it runs as to whether stuff went up the breather when the bike was switched off or fell over when it was off ( as happened a couple of times that day after the incident)
It appears the airbox end of that hose is completely open, thinking of re routing it above the airbox and putting filter foam on it. I am assuming the emulsification chamber (whatever its called) that you drain sometimes doesn't have anything in it stopping things going back into the motor? Given the top of the airbox is modded its pretty easy to get water in there.
I glued a bit of Scotchbrite scouring pad over the hole in the airbox that leads to the "emulsifying chamber". Saves doing anything more drastic
Ride safe, (and keep it upright in the water?)
Simon.
Higher than the airbox? Remember there will be a bit of oil blowing out as this pipe has the air displaced by the underside of the piston blowing through it every stroke, with oil droplets in it.
S.