I just saw this thread and thought I should jump in.
Yes, these are machine washable.
As far as the seats becomming a stinky mess... when the boat is home, the covers need to be removed and dried. Removing them takes just a few minutes.
When I camp, we hang them off the tower to dry. During the day, when the temp is near 80, they will dry in just an hour or so. When I drive home form the lake\river, I keep them on to trap all the rode grime. When I get home I wash and dry them, and then put them back on so when I am ready to go, so are they.
The covers are designed with lycra material between the seats... not terry. This allows that area to dry quicker and not trap in moisture.
I always dry the vinyl between the cushions when the boat is done for a few days anyway. This should still be done. Moisture between the cushions is the #1 place people forgot to clean, or don't maintain.
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