From my early PPL experience, a PA38 is notorious for taking huge quantities of water
into the fuel tanks, due to worn out filler cap seals. Anything up to a litre during a rainy night. That's really dangerous because the first few jars you drain are clean - they are 100% water!
They also take a lot of water into the cockpit, due to knackered seals along the top. I sometimes found 1/2" of water on the floor. This can make it smell like a public lavatory
