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Tuna hunting Pics

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Mr. Long Post
Apr 22, 2002
WOW !!!!

AMAZING.......318KG......If only I have a girlfriend, I will trade her for landing one of this.....:D


I have been deprived of a decent dial up speed for a very long time and today I just logged in again at DB. I must say your hunt is simply.....awesome.

To live up to my long post title, may I offer you some theory....:D to possibly make a more successful hunt for them giants bluefin ?

First of all, as our Kapiten Rig suggested, you must try an Alexander Slip Tip or a Riffe Slip Tip. These two been field proven for a long time.

Let's assume a detachable head, may it be a slip tip or a regular detachable spearhead as the priority for the giants you are after. It does have all the advantage over fixed spearhead. This spearhead is limited to a typical 500lbs breaking strength on its 2mm cable.

In my own crude calculation, a 200Kg Bluefin or a 318Kg bluefin has the same power level to break the available gear, if the hunting location is a deep water without any possible point of entaglement. If there is a possible entanglement, the heavier fish is definitely the KING of power. This is also based on a shot which is not stoning the fish, thus allowing it to demonstrate close to maximum power potential. My observation is that, most powerful pelagics at burst speed is capable of pullling power easily twice its weight in air. So, in my own assumption, a 150kg tuna can already break the 2mm cable ( 500lbs / 227kg ) used on most slip tip. This is also assuming that the flesh of the fish or perhaps the thick gill plate can withstand 227kg of tearing force appplied by a slip tip.

Calculating the 7 floats of 9 liters being used in your float system, the total floatation alone is already a whopping 72kg worth in sea water. Again assuming that the float can maintain its shape and thus boyancy for the first 100 feet, its non hydrodynamic shape will contribute to a great extra drag when towed underwater.....more so at say a burst speed of 30 knots.
The 100 meters of 14mm rope and the 16 meters of bungie will further add to the overall drag, not forgetting the shaft too. All this will multply in overall kilograms of drag as speed of the accelerating fish increases. The exact calculation method, I don't know. We need a hydrodynamic engineer for this.

I have worry that your current floats system may actually generate drags above 227kg when the fish is in burst speed mode. You must also remember that when a cable/wire is looped to attach it to a certain object, the inner diameter of the loop will be damaged first. A few strands of the cable will snap off bit by bit and thus reducing the overall strength of the cable. I have tried this kind of experiment by accident. I once shot a gun at water/nothing, with lots of rubbers and 500 lbs cable shooting line which was too short for the range the many rubbers could produce. I broke 5 strands. The same damage occurs to my slip tip cable after a big fish fight, a few strands of cable may get cut off. This could explain why only after an hour or so, then the cable snapped, instead of the first virgin burst speed.

However, we can make a crude experiment with ease for your float system. You must measure the overall drag of your float system at various speed, 10 knots, 20 knots and 30 knots. You will need a 30 knots boat. Sink your entire float line system, less the float. Use just enough lead on the end of the line to sink it nice & easy. Tie the end of the float line to a scale that can record highest reading, say a fish scale with a memory/lock. Get at least a 100kg scale. Put the boat engine in gear at slowest speed possible. When the float line is at 60 or so degrees in respect to sea water surface, gun the boat to 10, 20 & 30 knots. You may also wants to gun down the throttle all the way to 30 knots to simulate a first burst speed. Write down those values. Now we have the drag value of the float ropes & bungie.

Second test is to get the float drag value. Get a PVC tube which is closest to the diameter and length of your float. Plug one end of it to simulate your float shape front end, leave the other end open as the back end. Now tie securely the rope to this PVC dummy float. Test the drag value like you did on the ropes. Now we have a drag value of the rope set plus a single float at various speed. You can simply get the net drag of that single float and multiply that by 7 times for the 7 floats. If all these combined values exceed 227kg at say a mere 20 knots, you must remove some of the float/s or slim down the rope too.

If my memory serves me right, I used to spool out 800 yards of 50 lbs monofilament from my fishing reel to try to wind it up back pre-tension. I could never reel in back if the boat goes over 25 knots. Imagine the amount of drag a 14mm rope of a 100 meters at 30 knots ??

318KG is obscenely HUGE...... :p, I will experiment a great deal on my float system overall drag value if I were you. While we maybe tempted to place many progressive floats on such a big fish, we must remember that there is a maximum amount of force of the shooting line and the fish flesh holding power. If a Bluefin flesh is similiar to a Yellowfin, the meat and skin is not all that tough for 227kg of load applied by a mere 5" (12.5 cm ) of slip tip with 1.5cm maximum metal width. What kind of pressure per square cm being applied there ??... A LOT.

Hope you land those giants soon. Do keep us posted. Thanks.

One last thing, a few years back my friend experimented with a dry firing pneumatic like yours. Good to hear such units on the market now.....good power improvement.



New Member
May 2, 2003
Iya back

Nice to have you back Iya.....
youve been missed
Any bad ass doggie stories lately???


I should be working
Nov 8, 2002
Good info Iya. I would have never thought about things like those mentioned above. I think Rig has a good point with using spectra instead of cable. It is much softer, doesn't cut into the flesh as much, and the best part is has incredible strength to diameter ratio. I was reading in another post about reel lines and using some coated spectra in the reel. I wonder if they make some coated spectra which is 8-10 mm thick. The breaking strength would be insane but it would still be thick enough to grab and pull. One question to Fernando, are you guys fighting the fish in the water or do you jump back into your boat. I couldn't imagine trying to pull up a 300+ kg fish while still in the water. Just some thoughts. BTW welcome back Iya.



New Member
Aug 29, 2004
hi everybody, tuna experts.

hi I live in Israel and lately some fishermen from japan come to Israel to fish tunas with longline, and they even get alot of them.
Can ypu give me tips for tunas spearfishing, I understood that you chum on open water, but in what depth?
what do you throw in to the water?
do you use flashers?
any other tips will be helpfull...

thank you very much
icarus pacific

icarus pacific

Nov 7, 2001

IYA'S BACK!!!and all is well with the World. :)


New Member
Jan 3, 2004
I sent him an email a couple of days ago and he pm me today.Mr Long post indeed.


Mr. Long Post
Apr 22, 2002
Spearoo, W3AC, Uncle Sven & AJ...............yep it is good to be back......:D ...... and how is my favourite Kapiten Rig doing ?

Shane, you must have taken lots of fish all this time.....:p


Well-Known Member
Apr 22, 2004
I am getting serious about tuna landing.

I am in place again with heavier set-ups.

I could not take with me in the plane the bouys and i will manufacture someting here tomorrow. I have change my slip-tips to this :


i hope double 2mm ss cable direct to the rope will secure anything but a truck.

very good the long post !!


Mr. Long Post
Apr 22, 2002
All the best of luck Fernando.......
Please do not forget the video....me wants to enjoy the hunt too.

Let me save some money and learn from you next time how to shoot them bluefin in that location....:p
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