I tried them all and as long as it is strong and big you'll get more hookups. I like the Shout 7/0, Jigging Master 13/0, and Fishermens 13/0. There are other hooks out there that work well like Owners, Varivas, Gamakatsu, etc. but I do not like too heavy of a guage hook because they dull quicker and its harder to penetrate the hard tuna bone jaw.
I have been using the shout 7/0's for bluefin, they are real big hooks that aren't to heavy but very strong. Gman got me using them this summer and i have had great results with them since. The big hooks don't get tangle much and the tuna don't seem to mind them, I think they might even like the extra flash.
One customer bought JM assist hook from overseas from me by saying the JM hooks are the best Assist hooks he ever used.
But I am not picky about choosing assist hooks. Frankly I used OTI's ready made assist hook 10/0 mostly for big bluefin in 150 lbs - 200 lbs in Cape Cod without single problem.
I almost learned the hard way that a short shank is very important.
I had an OTI Raptor 10/0 Assist hook start to straighten on a 70" Bluefin. I don't think it was so much the gauge of the wire, as it's very stout, but under certain conditons, the longer shank allows for more leverage. The OTI's have a longer shank than what I use now, which is a 11/0 Gamakatsu Heavy Live Bait hook.
I suppose it matters where the hook is in the fishes mouth too.
I bet Pametfisher can figure this out mathematically. For every 1 mm of shank length the force of the leverage goes up X lbs..
I still have faith with jogging master hooks for tuna ad other species.
My first experiance with I'm hook was in cape cod where I was having problem with them staying inthe mouth of tuna. I later on learned that it wasn't the hooks problem but my problem is my own skills. I have yet to try otoko hook but I will get more of both hooks.
There is a member of 360tuna that posted a you tube video of the assist cord tying with new JM hooks. Just search :
Might be overkill (and slightly anal retentive) but no matter what hook I use, I apply some 1" sections of 3/16" shrink tubing to cover the thread. Gives a little extra protection when using pliers to remove hook and gives a more life to the hook. Costs next to nothing.
the gami heavy duty live bait is one serious hook. i have been using them for my assit hooks and have not yet had a problem. only question with these would be if you sacrifice penetration due to the girth.... happens to me all the time.
I've been using the Gami 11/0 4x strong HD live bait hook for my assist hooks for a while now. Started off using it for my sword rig hook but it doubled great for making assist hooks. Only problem is i noticed its so heavy it migh interferewith the action of some jigs.
I have had great service from 10/0Decoy Cutlass jig hooks my mates from Singapore MarkR bought for me when they came to fish NZ. Great hook and the biggest baddest Vertical jig hook on the market but I am starting to change to the 10/0 Jigging Master also a very good hook.