For open water I like to segment the leadcore because that allows me to hitch up my backing line (10 XT or 10lb FireLine) to a board. In open water using a board is critical.
The tricky part is deciding how much leadcore to splice in – which of course is based on how deep I want to run the baits. So, what I typically do when coming into a new fishing situation is have some reels set up with “full lead”. That is, I have 200 feet of FireLine backing, 10 colors of 18# Magibraid Lead Core line and then my leader (in open water 30 to 50 foot of Berkley 10 XT-the leaders will add depth to the lure. This will be in addition to the depth you get from the lead core).
Then I start experimenting with different amounts of lead to cover different water depths. At this time I actually attach the Lead Core line right to my Offshore in-line board. The Offshore board is ballasted and can handle the weight of the lead core – even right at the clip – be even so, it does not track out to the far quite as well because the heavy lead core will tip the board in a little – reducing it’s tracking ability.
Once I determine how much lead is getting the baits down to the right zone (1, 2…., 7, 8) colors, then I use a different reel to set up my “spliced”. Often here I put on half a spool (or whatever I think I can fit based on the colors I am going to use) of 10XT backing, then my colors of lead, then my leader (same leader I was using before).
Now, I can let out my bait and colors of lead and attach the 10XT backing to the board and the board tracks much better and spreads to the side more efficiently.
Remember also with spliced lead, if you do need to get a little deeper you can let out some of the backing to let the system run deeper. Of course the backing won’t bring your bait down as fast as lead, but the lead will continue to pull your baits deeper and deeper as you let out more backing.