Switching from 15 lb mono to 15 or 20 lb braid doubles your line capacity. I've gotten into the practice of replacing or reversing the last 180 feet of Fireline from time to time. I do a uni to uni to my backing line. 180 feet is approx 1/2 of a 125 yard spool of Fireline, so I get 4 "uses" out of a spool. Just have to be careful to measure it accurately.

If I'm out for a half day or more, I take either spare line or a spare rod and reel.
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If every fisherman would pick up one piece of trash, we'd have cleaner rivers and more access.