Depends on the design and the way you were using it. Did you get spray coming on board? Had it been outside in the rain? Water will obviously collect hence the bung.
Possibly through all the holes in the deck where the console and seats were screwed in. If it wasn't that who knows but it was getting in somehow, not in huge quantities though, a litre or thereabouts after a week of being on the water and open to rain.
My 490 also collected some water , maybe 3 litres or so in a good day out . If i had left it on mooring then I would have needed a way of pumping it out but for day use I didn't worry . It is anoying as i never found out where it came from iether .
One of the problems may be that some Valiants are delivered "pre-rigged" and some are rigged from a box of bits by the dealer - the water tightness of the hull then depends entirely on the skills of the dealer!
