On a regular bait caster and spinning reel you can measure out say 50 feet at home and take say a red sharpie and mark across the spool and then go out to 100 feet and take a black sharpie and mark across the spool and when you start seeing red come off the spool you're around 50 feet and when you see black then you are at 100 feet. Not precise but it will get you closer than guessing.