[xs_tackle]

Let the tackle store do it: Variable results. Welcome to the club; we've all tried this. Apart from offshore-sophisticated stores (rough test--display case shows more than $10K in 50# class "gold" or "silver" reels) w/trained employees, most of these really don't know what you need by way of spool prep/knot/winding.

Behind the boat--Good; we've all done it. But it has its problems. One not yet mentioned is the surprise of loading line fouled by soot or other discharges to the water from diesel exhaust (unless your host boat is running really clean) or mud/chemicals discharged from rigs.

Reel-to-Reel--maybe the best way to load spectra in the 50#+ range is reel-to-reel. But, when doing this, you'll see tension is not constant (only foot-lbs are constant). Because of the declining distance from the top of the line to axis of the source spool (effective radius) and the growing effective radius of the receiving spool, the operative drag on the sending spool is rising and that of the receiving spool is falling. Ideally, you'd like for them to be constant or you'd want the line nearer the bottom of the receiving spool tighter (to prevent digging). Using Uncle Russ' technique may mask this shift somewhat because of winding fatigue (or, errors related to motivational beverages used to offset fatigue). If you're using an electric line winder, the best practical way to counter this to readjust drag settings on both source and target spools 2-4 times during the winding process. If you're doing it by hand, you should not be able to dent the retrieved line with your fingernail.

If you use the reel-to-reel or spool-to-reel technique, you can do a better job by adding a step or two to the process--load first to a spool or reel under some, but not a lot of, tension and use an exaggerated back-and-forth motion in placing line onto the spool (giving a greater back-and-forth line angle or "pitch"). This cuts down on spool capacity but resists the tendency of the line to dig into the source spool when you're later loading the line (under even more tension) onto a reel you'll use use while fishing. When you later load from this spool, use bare fingers to guide the line into onto the target spool with a much finer pitch. Bare fingers because you want to be warned of the temperatures you're generating.