Essential items for daily fairweather cruising....

[Bern Hanreck]

short length of plastic strimmer cable ( for tickling troublesome tell-tales ! )

[GerryP]

"......A bucket......."

In an emergency, your grab bag I'm assuming will be a 5/10/20 litre size?
These keep water out - but could be used to carry water also.
If you need to use the dry bag in this mode, then you are in the mire anyhow!