Fish weight Vs line size

[wilcara]

OK here's something I have been pondering fo a while and somebody might know the answer.

Is there a ratio say of fish weight to strain applied?

What I mean is, say it is a 20kg fish. For a start, on one hand it does not weigh 20kg in the water. On the other hand it is not behaving as a dead 20kg weight, it is swimming away to try to escape. Maybe it is using currents/water depth and so on to its advantage, all of which weighs up on top of whatever it's water weight is.

How does this effect drag settings?

So how many kg of force would the 20kg fish (typically) exert on the gear?

I guess different fish would exert a different figure? Say every fish was 20kg then a tuna would exert more strain than a snapper for example?

So if there is a figure for this 20kg fish what is the relationship between that figure and a 10 kg fish, or a 40kg fish? Half or double?

What is the relationship to line size to fish size then? So if a 20kg fish exerts say 30kg of force (or whatever it is) then presumably that will strain a 30kg line to breaking point. (I know they overestimate for safety but it is a mathematical hypothetical)

Does anybody have a formula or guideline to decide what weight of line to use in a given situation/fish or is it merely a subjective judgement. i.e guess?

Should I just take my pills and have a lie down?

[spears]

Have you been missing your medication ??
That’s a good question that you’ve bought up.

I think you will find the answer to this when fishers have caught world records using light line..e.g.200LB fish caught on 8LB line.

No matter what formula is bought up only one thing that tears that apart is,fishing an area that should contain e.g. GT but will it be bigger and another species that takes the bait.

No matter what.. it’s upto the user to play the fish using drag.

I’ll just add one more point and that’s being prepared and not getting caught out or not being under powered.
As we have seen people buying stella’s etc and braid..
The idea is to have a set up which has controlled drag of some quality plus using braid in adding line length and a nylon shock leader .
A set up like that and you should be able to bring in 90% of your hook ups and not worry about xxxLB fish to xxLB line

[tunaticer]

I think that all fish can exceed thier weight in pulling power for a burst, the reason why we have developed drags so line can be fed out automatically below the breaking strain weight. I suspect however that this peak is very shortlived as fish in thier environments are not load bearing creatures and do not need huge reserves of stamina in thier environments. They simply eat enough to have the energy to find something else to eat for the large majority of thier lives.

Sustained efforts i would think would be in the vicinity of about 1/3rd thier weight as a maximum amount of line pull they would generate and sustain for more than say 10 minutes.

The pound for pound ratio on which fish fights the hardest is not fair on the fish. Some are speedsters, some are slow and powerful and some fight to the death and are not a challenge because of thier size and our size relationship.

For my money the fish i like to fight the most is jewfish because it is a holy grail of fish to me. Jacks are ho-hum to me, caught enough for a lifetime and cant be bothered targetting them these days. Snapper are not much of a fighter but are good for the table so thats currently my target until salinity levels return to areas i want to fish.

[wilcara]

So guys, how much force do you think a 20kg tuna can exert?

[snagking]

So guys, how much force do you think a 20kg tuna can exert?


Alot?;D

No idea, never got even close to a 20kg fish

[CreelReaper]

Wilcara, to answer your question…….take your pills and go and lie down mate.;) ::)
Better still, take a number of rods out fishing with you each of which is of differing line rating. Say 1kg to 5kg. Experiment on your local table fish and see how low a line class you can go (using the same rod type) before losing a fish.;D
Mate, it would be virtually impossible to come up with an all conquering answer for every fish. As stated above each species is different.
In simple terms Force = mass x acceleration. This though is thrown out with the bath water because you have so many variables working either with or against you. The mass is not constant as all of the contributing factors will add or subtract throughout the exercise……

The physical size of the fish, it’s acceleration rate, how well it is hooked i.e. lip or gut hooked, direction of current and speed , initial mass of weighted bait also adds to the force. Add also the diameter of the line, the condition/age of the line, the amount of line being bellowed by the current/tide and the ‘rated stretch’ of the line.

Changes in direction of the fighting fish – down current, up current, straight to the reef, or heading for the horizon, whether it moves side on to fight or just uses that initial burst of speed to ‘escape’.
Now look at the terminal tackle and rod being used. Are the guides in good nick, and free of rough or sharp edges? Is the rod a slow or fast taper? What length is the rod and what “cushioning” effect does it have in these erratic movements the fish make therefore ‘aiding the line?? In other words is there a frictional force anywhere in the system working against you???
Mate, you could hook a once in a lifetime ‘jewie’ in a river system and with patience most likely catch the beast. Put that same fish in the surf or outside in 100m of water and it will perform totally differently and likely blow you away.:o

This link will give you some reading in the quieter times mate....enjoy

http://www.sportfishingmag.com/techniques/tips/20--line-test-23589.html

Shane

[TimiBoy]

Mate, I'm inexperienced and fairly well sozzled, but I'm giving an explanation a go:

You can just about catch any fish on any gear. I've seen on the telly a 40lb Ambo taken on 2 lb gear. My mate picked up a 200 lb Marlin on 20 lb gear - took him 6.25 hours, so he says...

It's all down to technique and the team. Technique will allow you to play the fish, the team will position the boat/net/gaff and give advice/bring drinks to help land the big one.

Time and experience will show you what weight of line and drag you are comfortable with - it's a balance: how fast do you want to get 'em on board, how patient are you, what risk of bust off are you happy with? I've asked lots of questions, and there are as many answers for my region as there are people. That's one of the great things about fishing!

Is that Charter Special catching fish?

Cheers,

Tim

[finga]

The answer would in the way you tell porky pies.
If your good at it (telling porkies that is) then a 200lb fish only needs 2lb line and a whiting rod.
If your bad at telling porkies then you need whipper snipper line and a broom stick for that same 20lb fish.
Another factor nobody seems to think about is which side of your face is your tongue hanging out.
It's a known fact that you can use smaller line and gear if you hold your tongue out the left side of your mouth.
It's true. Try it.

[wilcara]

I wondered if asking a serious question to a mob of Queenslanders was a wise move. ;D I should have known, its Friday, Queensland will be p!ssed until Monday at least.

I do enjoy you mad b@stards though...

Lets simplify it a little: How hard (in kg) could a 20 kg tuna pull??????

Timi it has a couple of friends now and is in very good company, I like the three of them very much. I just ordered three reel clamps that Shimano make especially for charter specials. Your little baby will see action soon. You got any more????

[yanjarra]

OK here's something I have been pondering fo a while and somebody might know the answer.

Is there a ratio say of fish weight to strain applied?

What I mean is, say it is a 20kg fish. For a start, on one hand it does not weigh 20kg in the water. On the other hand it is not behaving as a dead 20kg weight, it is swimming away to try to escape. Maybe it is using currents/water depth and so on to its advantage, all of which weighs up on top of whatever it's water weight is.

How does this effect drag settings?

So how many kg of force would the 20kg fish (typically) exert on the gear?

I guess different fish would exert a different figure? Say every fish was 20kg then a tuna would exert more strain than a snapper for example?

So if there is a figure for this 20kg fish what is the relationship between that figure and a 10 kg fish, or a 40kg fish? Half or double?

What is the relationship to line size to fish size then? So if a 20kg fish exerts say 30kg of force (or whatever it is) then presumably that will strain a 30kg line to breaking point. (I know they overestimate for safety but it is a mathematical hypothetical)

Does anybody have a formula or guideline to decide what weight of line to use in a given situation/fish or is it merely a subjective judgement. i.e guess?

Should I just take my pills and have a lie down?

haha ..thats awesome wilcara... couldnt of produced better myself..champ...go the storm just quiet

[spears]

I'll have an answer for you shortly..



OK here is some guide without KG’s showing:

“””The weight of a tuna is largely irrelevant to how much force is exerted on the angler. The variables that determine force (maximum) on the angler are as follows:

Drag setting
Rod Length
Rod Angle

Of course, if the fish is not strong enough to pull drag, then you replace drag setting with the straightline force at the reel generated by the fish.””””

So in reality The pulling power and the force of the fish to what the angler gets in KG’s is controlled by the angler.

……………How hard (in kg) could a 20 kg tuna pull??????...........
In summing it up it’s you that decides KG force.


I know it's not quite the answer your looking for but i'll get it eventually.Back soon

[tunaticer]

You could grab a 200lb handline and tie it off to a loadcell and monitor the forces applied by the fish if you really wanted a definite answer. Catching a 20kg tuna on the handline will be your challenge. Not getting hit by the lure when it rips free from the fish could be a possible reality.

My opinion still rests at close to its weight factor.

[TimiBoy]

You could grab a 200lb handline and tie it off to a loadcell and monitor the forces applied by the fish if you really wanted a definite answer. Catching a 20kg tuna on the handline will be your challenge. Not getting hit by the lure when it rips free from the fish could be a possible reality.

My opinion still rests at close to its weight factor.

I don't know about that - 9lb of Kingie pulled line off a 15lb drag setting on me on Tuesday. Not much, but it did get some, maybe a couple of metres a couple of times on the way up. He did yank me a bit (maybe more of a balance issue) towards the gunwhale, too, and I weigh about 220 lb.

Do Tuna weight for weight pull harder than Kingies? The only Tuna I've caught (20lb) stripped a fair bit of line at around 20 lb setting, but it was a fairly easy catch in the end on 50 lb mono.

There are a gazillion variables in this question. It's a good one!

- fish fat or fit?
- what food it's been eating?
- water temp?
- water oxygenation?
- recently bred?
- and others I'm sure...

Cheers,

Tim

[PinHead]

Is the breaking strain of line rated for the linear force or sheer force????

[PinHead]

I wondered if asking a serious question to a mob of Queenslanders was a wise move. ;D I should have known, its Friday, Queensland will be p!ssed until Monday at least.

I do enjoy you mad b@stards though...

Lets simplify it a little: How hard (in kg) could a 20 kg tuna pull??????

Timi it has a couple of friends now and is in very good company, I like the three of them very much. I just ordered three reel clamps that Shimano make especially for charter specials. Your little baby will see action soon. You got any more????


You too would drink a lot if your nearest neighbours are a few million New South Welshmen...but we love em...always great when lil brother beats the crap out of big brother in State of Origin.

[wilcara]

But my neighbours ARE New South Welshmen too!

[wilcara]

OK guys if we try to take all the variables out, just so we can establish a baseline, or quess at one really. Assume that fish are all the same size/fitness/shape/weight etc etc, teh hook is solid, that the water is still with no currents and so on, that there is no rod or angler, so the line is fixed to an immovable object like a pier, and minimum stretch so maybe 50m out. What size line will that 20kg fish be able to break?

[finga]

Is it heading to the pier or away?

It's a long week-end too matey.
Have another base line...what fish species?

[Owen]

Wilcara,
Get a dead fish. Put a hook in it and attach it to your scale. Throw it overboard.
That's the pressure the fish's weight exerts.
The presure a LIVE fish exerts would have more to do with the surface area of it's tail, the force it applies when it moves it's tail etc etc.
Waaayyyy to much thinking to work all that shit out.
Just drink ya beer and fish!

[GBC]

If you're going to tie the line off and not use drag, then it's going to be subject to dynamic loading forces as well, when old mate 20lb and 200mph finally pulls the kinks out of that handline.......:P
I've caught large yellowfin on handline (netting twine anyway), and suffice to say - they pull a LOT, and even now at 38 y.o and being fairly fit - I dunno if I could do it again. Even if I could I dunno if if I'd want to - it just isn't fun after 10 minutes.
Only one thing pulls harder than a tuna and that's a dolphin. Accidently hooked one once and goodness gracious it smoked - up until when I identified it and felt like the world's biggest pr!ck.
Wilcara if you think about this too much you're going to need either more meds or John Nash (A beautiful Mind).

[wilcara]

I'm sorry to say that this really is doing my head in.

You see, in Victoria this time of year, as at most times of the year, the weather is crap, and the potential for fishing is even crapper. So what do fishermen do? They think. Thinking can be a bad thing, as in this case. If I was further north I would possibly be out fishing, drinking that lumpy beer in the sunshine and trying to learn what the heck the point is in that strange game you guys get so het up about. However I am stuck here in my cardigan watching the weather forecasts and contemplating the distorted contents of my head.

So far we seem to agree that a fish exerts far more force than its weight, depending on fish build etc.

If a 9lb kingie is pulling off 15lb drag then it is exerting twice its weight in force. So if the drag was locked one could assume that the 9lb kingie would snap a 15lb line. In which case to fish for a target of say up to 10lb kingies you would need to use minimum 20lb line?

A fish that breaks a 20lb line is not necessarily 20lb weight but exerting >20lb force on the line. A combination of factors but from the above example a 10lb fish? Could a 5lb fish exert sufficient force to do this?

So to catch a 500lb marlin on 65lb line is because the angler is eliminating peak forces by the skill in evening out the pressures; the stretch in the line; quality of the drag; and cushioning effect of the rod; not to mention the skill of the skipper in manipulation of the boat position.

If you are skull dragging a sluggish fish like a Murray Cod that weighs 100lb it is not exerting 100lb force because it does not weigh 100lb until you take it out of the water. So say it weighs 50lb worth of resistance while submerged and does not fight then it should not break 50lb line?

But if it fights then applies force at the same ratio of the Kingie (above) it would exert double its actual weight which would be 200lb force on the line?

Mmmm...

[PNG1M]

Spearsy has a good point though the explanation is a bit demanding on the brain cells (subjective reasoning required there).

I get the gist of the 'angler' being the main influence on the fishes pulling power. Consider the variables:

1) If you have a 20kg tuna in the open sea and a good reel with plenty of drag & loads of line you can let the fsh run and you can play it for hours. Hence the fish wouldn't be able to exert much pulling power as it could only pull as much as the drag setting allows.

2) If you want to get the 20kg tuna in the boat quick smart and you lock up your drag and engage in a man-on-fish 'tug o war' then you'd encounter a much greater deal of force.

(So back to the original question --> how much force 'could' a 20kg tuna exert? We need to think of how 'measureable' this force is. I dunno...)

PNG Black Bass are renown as strong fighters & ruthless on tackle. I've caught a fair few so I know. BUT part of the reason you're always up for a good fight is that you gotta get 'em in quick.

Hence you don't have the luxury of 'playing' them for ages in snag free open waters. Hence, the angler will experience 'hard pulling' fish exerting greater force due to heavier lines used & increased drag pressure.


Any of that make sense....geeze where's those pills got to?

[GBC]

I'll have another go -
We'll need to know how fast the fish is travelling, and how much line is out also.

Fast fish can travel so fast that when they change direction through the water the force they can exert on the bowed fishing line dragging itself through the water can 'pop' the line - ie exceed the line's breaking strain - and this is without any angler input at all - in fact he/she is probably still watching their line in the water at the back of the boat and the real action is out the side of the boat 100m away.

Line drag however - can be one of the angler's best friends when fighting in clean water as it wears the fish out but not the angler - until retrieval time.

How else can I put this -

I just spend Sat/Sun off the Gold Coast Fishing. We were travelling between fishing spots at around 20-21 knots. Being exceedingly drunk at the time and not wanting to waste fishing time - it was decided to run a couple of hex heads just in case there were any errant and exceedingly fit spaniards left in our part of the world.

The largest sized hex heads were used, and to keep them from continuously blowing out they were run a loooong way back (100+metres).
The drag required to stop just the lure and line from stripping more line from the reels was well past strike and probably 3/4 the way to sunset on 24kg diawa bent butt outfits.

Now deliberately chasing spanish on 24kg might seem a little rude to most, but those reels were the only one's running enough drag to cope with the lures at that speed.

You might be surprised to know we got nothing but more drunk.8-)

[PNG1M]

How about a controlled experiment where someone can tie a length of line directly onto a set of calibrated scales then put a lure (or bait) on the other end & chuck it over the side of the boat..!?

Then when a fish latches on you can read on the scales how much pressure it is exerting while its pulling. If you're lucky enough to land the fish, you can weigh it then calculate the ratio between fishes weight & pressure it exerted.

Do this often enough over time, for the same and other species and record the results. Then get the 'average' of the weight vs pressure ratios and vwalla...

Next, find a good fortune teller who can predict the weight of the next fish you're gonna catch & you can spool up with the appropriate line size to ensure a fair contest!?


Crikey, those pills must've kicked in!

[wilcara]

Now your'e talking! No point me doing it, I can never catch anything.

[rockfisho]

Wilcara, just on this topic of force / weight business. If you are after some ideas, it would be helpful to know the physics behind it first. It is easy to catch a fish heavier than that of the line weight being used. Rather than considering forces. (if you do, this is a very complex calculation, involving fluid mechanics) It's much easier to consider work. Certian fish can exert certain amounts of work. (work is just the force applied times the distance its applied over) therefore, hypothetically, if you halved the drag but doubled the line length, you could still land it. power also needs to be considered (time rate of change of doing work), as a fish like a tuna is more happy to cruise rather than bolt, and can do for much longer proportionatly.

but overall, worrying about all this stuff is really quite pointless. if you want to skull drag fish in, i suggest experimenting with line sizes, alot of it comes down to this.

cheers

Owen

[Mikeey]

i remember watching a doco about this, they were doing the test with sharks so im not sure how many fish would match this, they found out that the sharks could pull half their body wieght, so a 100kg shark would put 50kg of pressure on the line, but then using drag and wearing the fish out it wont be able to put that pressure on the line etc....

hope this helps

[BarraBandit]

Guys,


You need to remember you are using drag... there is more factors to be added in than just the line weight.

I have pulled 12lb fish in on 4lb line, It takes longer than using 15lb and just skulldraging it in, but it can be done.

Line strength doesnt just work on straight pull, like putting a 5kg weight on the end of your line and letting it sink to the bottem... You need to factor in Tide/Current, Knot strength, How big the fish is, Are you fishing structure, Size of the tail (some fish are for speed, aka wahoo, and some are for pure power, aka barra)... and thats just the basics. You also need to think about what line you are using, mono or braid, and in some cases what brand!




Who ever said fishing is just luck?






Bandit.

[Jeremy]

i remember watching a doco about this, they were doing the test with sharks so im not sure how many fish would match this, they found out that the sharks could pull half their body wieght, so a 100kg shark would put 50kg of pressure on the line, but then using drag and wearing the fish out it wont be able to put that pressure on the line etc....

hope this helps

That is quite interesting. My opinion would have been that most pelagic fish could pull more than their body weight.

ie for your 20kg tuna example, it would break 20kg line. I reckon that would definitely apply to mackerals, all tunas, trevallies, snapper also. I am talking about from a standing start, not hitting the line at speed (inertia).

Just my opinion.

Jeremy