Problem is, do you really NEED a Jon line?
I have to tread carefully, here, as Jon Hulbert is a local (to me). Never met him, never tried to. I'll never ever dive in his circles. I do have a picture of him and his buds on the Bow Mariner. Have a flag too. Pic was autographed by all but him. Dive meeting raffle, fun stuff.
Anyway, see pic. It is one of our local versions of the Jon line. It is great for shooting heavy goodie bags and the occasional recovered Danforth anchor. Make sure that the clip can pass through the ring. Several ways to secure the line on the bottom and still be able to run your reel line through it. If you F* up or your reel jams, you aren't going anywhere. Getting pulled off a wreck in the NE Atlantic can make you really unpopular very fast.
Notice the whipping on the finished product. Use nylon line, you need the stretch. No knots, just pull the ends with pliers and cut off flush. They retreat back under the coils then you dress them with neoprene cement. Whip the top and bottom of your splice.
Learn that splice...
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