I showed you the mako tracking because most the tracking is of juveniles none breeders that prefer warmer waters than swordfish above 64-F +or- a few degrees.
There are several factors to consider one being a lot of gill netters in rough seas do not use harpoons because it's a hazard in rough seas and very difficult to see finners basking in rough water.
Gill netters prefer water 58-65-F very similar to tuna conditions on big breaks for several reasons. with 40' planks off the bow.
Prey can not cross a break or they will go in to shock or go deep because of the thermocline or the the cooler water will aging cause them to go in to shock.
these barriers act like walls for predators to herd and trap prey corralling them pinning them down kind of like shoaling them.
The warm side of the break is a predator comfort zone making it possible for the swordfish to comfortably relax and recharge their batteries resting and digest their food much faster after foraging deep on cold prey reducing their core temperature. In the warmer water they can digest pert much faster and warm their brain and eyes back up to maximise their advantage over cold blooded slow half frozen prey hideing in low light levels deep compared to prey near the surface at night is much warmer and much faster with improved vision.
the swordfish has a big advantage feeding deep during the day verses night as a result of the swordfishes heater for their brain and eyes that have functioning pupils like us.
The cold side of the break you can see all the chlorophyll from the satellite charts telling you where most of the food chain or food web is likely to be concentrated but remember the chlorophyll is also under the thermocline not visible on a satellite chart something very few anglers are aware of.
Most of the oceans biomass is congregate below these chlorophyll maximum areas rising and falling with light levels day night moon weather clouds etc,. visible on a depth sounder so you know where to present baits day or night using a line counter to match the depth from the depth sounder.
This food web or food chain on these breaks is a primary predator gathering location like a water hole in the desert.
That is why commercial guys target them and if the do understand these principals they will not share them.
now with this in mind when you are reading different information from different fisheries regarding swordfish oceanographic conditions keep in mind if you are near shore like in the so cal bight upwelling system there are a different animal and open ocean in the central north pacific ocean north of Hawaii where they are really primarly targeting tuna with a much deeper thermocline than say nor cal you need to tease out the important principals pertaining to your fishery with a shallow thermocline with no bottom way off shore unlike the near shore upwelling in the so cal bight and north and south flowing currents to consider and gyres.
lets look at what conditions the gill netters target in central California and sometimes in northern California all depending on the season SST and chlorophyll and prey spawning areas etc. that have a lot of seasonal consistencies but also have a lot of environmental variability
influencing a vast amount of variability's that are not impossible to understand and dial in if you keep up with the variability's on a regular basis including history current reports etc. with an understanding of swordfish preferences migration and biology also influenced by their mass.
Basically understanding when the swordfish could be in your range of your fishery is the same as when the albacore water moves in a big break plume with lots of life big food web chlorophyll 58-65-F would be a primary gill net target when they push in you range.
when you have these conditions push in and you hammer the tuna stay and drift in the middle of the life with live bait using chum from new fish all at night above the thermocline visible on the depth sounder.
swordfish are opportunistic scavenger one tooth sniffer dog sharks that come in on chum just out side the lights from the boat tripping on the smell of good chum action and live bait will usually keep most of the blue sharks away.
make sure you use a chem light so the predators can find your bait first and not chase the prey around the boat that is pigging out on all the chlorophyll from the lights gathering the chlorophyll.
Lights gather plankton and prey eat plankton who chase whole school of prey away from your dinner party, getting tired and filling up and going away chasing prey so using light is a great idea to gather a food chain web at your boat leading right to your chum slick and while chum is in one direction sound travels in all 360 directions from the generators ringing the dinner bell so raise hell and bring the predators in using light and noise is good but sometimes total darkness works well to pin pointing the light stick as a focal point in all that chum smelling so good so they do not chase all the bait balls and prey away making noise to attract predators because the more noise and light the better to ring the hell out of the dinner bell.
when the prey around the boat in the lights splits there is a predator around get ready.
day time deep drop is all about the depth sounder looking for the scattering layer and life being balled up, use a line counter and drop to that depth and give it a try.
in you see deep diving Russo's, elephant seals etc. you are in an area where there is abundant deep scattering layer prey that will hold swordfish and tuna.
if the tuna are not chewing up top when you do get a tuna open it up and see what they are feeding on from the deep scattering layer prey and deep drop and drift to that depth.
do i think swordfish are available in your area ? yes i do and i would target my effort when the tuna water pushes in range but swordfish style not tuna style in deep water during the day where there is lots of prey deep most likely the bigger tuna will be feeding deep because the tuna and swordfish have internal heater to warm their brains and eyes with dilating pupils giving them a big advantage over cold blooded slow half frozen prey that are a lot easier targets than prey up top at night.
The larger the predators the more mass they have to keep warmer loner than smaller predators who get colder faster causing the smaller predators to feed up top more and bigger predators can feed a lot deeper a lot longer on slow cold fish trying to hide in the dark.
Squid and other fish are transparent so they can reduce making a silhouette blocking out sun light when predators are below them in deep water looking up for their silhouette.
Prey use bioluminescence to match the hatch of the light levels around them to blend in reducing their silhouette as they sneak up to the bottom of the sun light zone and sneak some plankton food or scooby snacks while elvis is looking at them like a bacon peanut butter sandwich.
Chumming at night is critical when swordfish are up top in low light levels,with out a chum wall miles long you only have attractors out as far as your lines and a limited amount of oil dissipating from your bait.
a gill net is 1 mile long and 30' deep incredibly increasing their chances of catching fish, imagine if their net was only a few feet square equivalent to a few baits drifting with out a few miles of chum.
If you are drifting 1-3 knots at night when the swordfish are up top usually above the thermocline in an area where tuna was during the day and lots of life on the big break dragging chum buckets choke especially in windy conditions you could easily be out attracting a 1 mile 30' deep gill netter with a chum slick tuna, swordfish, Opah attractor miles long behind your boat drifting attracting everything to you instantly enhancing your opportunities.
sure the unwanted sharks will show but they are usually lazy and will not chase feisty baits like big deans of mackerel especially if the bait can out swim them assuming you do not have to heavy of gear slowing them down.
trolling at night in high chlorophyll areas can create a unnatural wall of bioluminescence light freaking the predators out.
i have placed my baits just inside the 3000 watts of light so no bio was illuminated with success and lighting up well with light sticks to hide the unnatural wall of bio light from the trolled mono line.
OK enough for now hope this helps and i would like to come up in a few months and see if we can find and catch some of the salmon sharks it's so expensive to go to Alaska and catch them.
these are just some basics principals but relative to what you are up against to my understanding.
Hopefully i have my new boat soon and i can fish outside longer in rougher seas.
she could have a range over 800 miles to my understanding