Planning a trip to Ishigaki Japan in April, but the budget airline I'm taking is notorious for their 7kg carry on limit. I'm looking to save weight by using a duffel instead, but was wondering what other options people are using especially regarding weight.

 This issue is discussed often and it’d be worth searching on Waterpixels. Backpacks, fishing jackets, tears and pleading, carrying cameras/housings on shoulder straps are amongst the many suggestions offered.