A pair of 4L IPX6 Waterproof Bikepacking Fork Bag, which also double as dry bags. Perfect for kayaking, canoeing, and any time you want to keep your gear dry.
Capacity: 4 liters / 1 gallon each
Product details:
https://www.decathlon.co.uk/p/4l-ipx6-waterproof-bikepacking-fork-bag/_/R-p-336343?mc=8669980
Installation (as fork bag):
https://www.youtube.com/watch?v=Sz5EMYFg4B8