Often while kayak fishing offshore, I use a vertical or Speed jigging technique from a kayak… What you need is a high speed reel, no backing braid ready (no slippage), and a jigging rod of your choice. I use Ugly sticks just as light and strong as the big names at half the price. Braid line 40-100 lbs (I use 50 lbs) leader can be mono or floro 60-100 lbs (I use 80-100 lbs) floro a little stiffer and holds up to structure a little better.
Knots you can use are Albright or Uni... Now for jig’s there are lots of different types, flat jigs have more of a flutter action that promotes instinct strikes or reaction strikes and takes longer to reach the bottom. The longer rounder jigs have more of a darting action, gets you down to the bottom faster. The jig weight depending on current and depth, If in 100-250 ft I use 5 oz jig if current is strong I will move up to a 7 oz jig.
Now for the actual jigging while free spooling your way to the bottom pay attention to the rod tip, you can get a strike on the way down. Once the jig reaches the bottom I like to work it (bounce it off the bottom) a few times before I begin my retrieval. What you want to do is make it all one motion, rod-up reel-down rod-up reel-down if done right you will have no slack in the line and you will not wrap your line around the tip of your rod.
Color of jig is all up to you; I use blue, pink, green, fire brick, combo of colors and also glow in the dark. If one does not work switch it out for another color. Once you get use to the motion you can experiment with different speed retrievals. I usually bounce it off the bottom and come up slow, when about halfway up the water column I crank up the speeds and motion. Go to you tube and watch some videos so you can see different techniques. Now get out there and practice.