What a twat I am

[rogerthebodger]

First get some water detecting paste and dip a stick into it and dip the tank. A change in colour will tell you how much water you have in the bottom of your tank. Once you know this you can decide what to do.

http://www.kolorkut.co.uk/

 

[lw395]

Most boats you can shove a long tube on a pela down the filler hose.
Try to find a tube of the right stiffness, or tyrap the tube to a length of sail batten or something.
Heel the boat to put the tube at the low side.

 

[ex-Gladys]

Not sure about the collection of rainwater calculation, what about the area of the deck that the rain was hitting? My fuel filler is nearly vertical, but water is in the deck, and the way it was raining Saturday pm, a load of rainwater would have gone down them...

 

[thinwater]

Oil change vacuums work great for such small volumes. Stuff the hose down the filler to the bottom and pump a few quarts.