OK I want to discuss a pet peeve of mine with Shimano and other reel makers.
IMHO the "drain" holes let in more water than they ever drain out. I have done simple splash test with my reels where reel is not "dunked' but only splashed like when we wade (please check the accuracy of my test yourself). Low and behold there is water in the reel in about the worst area, behind the main gear and on/against the drive shaft bearing. This is the most in accessible place on/in the reel for maintenance yet closest to an opening for water to enter? Does this make sense?
Examine used reels all the 'boat rash" is on top which means most reels spend alot of time with the holes pointing upward waiting for splashs to get in. Not many have much "boat rash" by the drain holes.
Can't they consider for an upgraded reel one that has a much better sealed main frame enclosure to keep water out? How about just some small plastic/rubber plugs that can be removed to drain water out if/when the reel actually get dunked/filled?