Suspending Jerkbait Depth?
16 replies to this topic
Posted 06 May 2009 - 03:20 AM
I have heard people talk about temperature affecting the way a jerkbait suspends but what about water depth? If I have a pointer 100 that is supposed to suspend between 4-7 feet shouldn't that lure slowly sink until it is in that depth range? Does the water get more dense allwoing the lure to suspend at that depth? I have a few lucky crafts that slowely sink and I wonder if that is why. I am trying to tune some Jerkbaits from janns and predator to get the same suspending action that my 100 pointers have. Thanks for the help.
Posted 06 May 2009 - 07:53 AM
Yes, temperature affects the density and suspend depth, warmer = deeper. Other attributes that affect the depth are the salinity of the water, all fresh water has minerals in the form of salts dissolved, so the depth will vary from lake to lake. By how much these parameters effect the depth, I am not sure, but 4 - 7ft seems a reasonable spread.
As far as adjusting for neutral buoyancy, I found that 1/200 of the lure weight is the fine adjustment increment, so a 40g lure, the fine adjustment would be 0.2g.
Lures for use in sea water would have to be re-designed, if employing neutral buoyancy effects. Density of lake water is close to 1.0000, sea water is 1.0250.
Here is a web link that discusses the subject: Density of Ocean Water
Posted 06 May 2009 - 01:45 PM
So when people complain about their suspending jerkbaits sinking, they may in fact be working correctly once they get to the 4-7 foot range? I would think testing lures in a bot or bowl would be inaccurate in finding weather it suspends at the lures correct depth.
I also have a LC pointer 100 realskin that sinks somewhat fast in a large bucket when all of my other lucky craft lures will slowly float to the surface. But from fishing a clear lake I find that the realskin sinking LC will suspend where it is supposed to in the 4-7 ft level. Any thoughts on that? Thanks for all of the help.
Posted 06 May 2009 - 02:17 PM
It could be down to mineral salts. The only way to know for sure, is to take a hydrometer to the lake next time and measure the specific gravity of the water. Knowing the specific gravity allows you to duplicate the conditions at home, by adding salt or sugar to your tap water and match the sg (specific gravity).
A cheap hydrometer can be bought from home brewing or health shops.
Posted 06 May 2009 - 02:43 PM
I fish these jerkbaits in high lakes and rivers at around 4,000 ft above sea level and the water temp is 50-60 degrees. Thanks for the information!
Edited by steelheadstalkers, 06 May 2009 - 02:50 PM.
Posted 06 May 2009 - 07:37 PM
Altitude could possibly affect things too.
We have gotten heavy on this subject before, here on TU and you have just introduced another variable, altitude, that we never considered before. I can feel a severe headache comming on, so I am not so sure I want to go there.
Some things to consider: water is close to being incompressible, so the altitude probably doesn't change much. Air on the other hand, is very compressible and altitude makes a big difference. Another consideration is gravity. I did a google on this one and although the gravity value does change, the error is around 0.9% at 30Km height, so again, insignificant.
But instead of wandering off into the realms of physics, we should try to keep to reality. It would be nice to know what the sink rate at the surface was, knowing that the bait reaches neutral at say 5 feet. A swimming pool would be nice, unfortunately, I no longer have access to a pool. My point being, as you suggested, the rapid sink rate in the bucket might well be correct.
Posted 06 May 2009 - 08:10 PM
I appreciate your input. I read some older posts about this and it looks like paint and clear shouldn't affect the weight much. If I have a lure with all the hardware on it before painting and it very slowly sinks then when painted it would only sink slightly faster then? I will paint my jerkbaits and set them up for a slow sink since most of the time I am using them for big brown trout and do a lot of casting and jerking along with trolling which neither of these are affected by a very slow sink plus they could actually suspend at the 5-7 foot range. Thanks again.
Posted 06 May 2009 - 11:28 PM
I think suspending jerkbait afficionados take as granted that their jerkbait may need to be adjusted with Suspenstrips, etc "on the day" depending on water temp, type and size of line used and "whatever". Yes, a bait that suspends at exactly 7 ft in 50 degree water will eventually sink to that depth because the water above 7 ft will usually be warmer, in which the lure is relatively less buoyant. But that's not useful in a practical sense. If you float test a bait and ballast it so it suspends in a bucket of 50 deg water, that's as close as you can get it in practical terms. You'll fish it on a floating superline, mono, or sinking fluorocarbon, so adjustment will probably be required anyway to get a true motionless suspend.
Posted 07 May 2009 - 01:28 AM
It does not mean the lure will simply sink until it reaches the 7ft mark and magically suspend. It means the bait will run approximately 7 feet and is a suspending model. Most will actually float to the surface, some faster than others.
Posted 07 May 2009 - 04:50 AM
Chad - With all their whiz bang technology, they can't keep a satellite in syncronis orbit for more than a couple of months, without having to adjust it, so what hope have we of keeping a lure at 7', using a bucket in your laundry, then taking it up 4000' and then add the water temperature variables or probably 40 F from Summer to Winter.
Like the plastic 'subs' we had as kids, drill a hole and stuff some bicarbonate of soda in it, at some stage it will hit 7' .
Eventually we have to think around these things.Pete
Posted 07 May 2009 - 07:58 AM
The beginning of the post wasn't to get a jerkbait to magically suspend at 7 ft. I was simply talking about lucky crafts jerkbait information and wondering if that is why some of my LC slowly sink to the desired depth. If not it should say on the package suspends between 0 and 8 feet becuase it would suspend just after it hits the water. I was just seeing if some of the jerkbait blanks I had could start to suspend at the 4-7 foot range that the lucky crafts do. I unlink many dont realy care how well it suspends as long as it only slowly sinks or floats because the way Im fishing them isnt better one way or the other, within a few minutes it will be back at the boat! Thanks for the help on the subject.
Posted 07 May 2009 - 12:02 PM
Water temp makes a big difference but I don't think other environmental factors have much effect (except fishing it in fresh vs salt water). I'd bet the reason some sink slowly is more often variability in manufacture or user specifics. If the user changes the trebles or split rings, or uses a type or size line different than a "control sample", he changes the outcome. To me, a jerkbait that suspends in room temperature water is probably best. I'm going to fish other, non-suspending baits in warmer water. In cool or cold water, I can add weight, change from mono to heavier fluoro, or to a thinner diameter mono. There aren't so many options when trying to get a sinker to suspend. But in real-world fishing, you're right on. Unless you're pausing the bait for 30 seconds or more between jerks, it ain't gonna matter all that much and dissecting all this is like talking about how many angels can dance on the head of a pin - which is one of our favorite pastimes here on TU:lolhuh:
Edited by BobP, 07 May 2009 - 12:03 PM.
Posted 07 May 2009 - 01:15 PM
Occasionally exploring the nitty gritty can come up with something useful, but basically I agree with Bob. I am a bad one for dragging simple subjects into the depths of obscurity.
Posted 12 May 2009 - 01:17 PM
There's a few things that affect how well a lure will suspend. You can take 5 different suspending jerkbaits, put them in the same water at the same time, and they'll all have different bouuyancy. The biggest factor is water temp. The warmer the water, the more the bait tends to sink. But remember that water starts becoming less dense again below 41 degrees, so the a bait that suspends perfectly at 41, will sink at both 40 and 42. Hooks, split rings, line also will affect it. Plus dissolved stuff in the water affects the water's density. Also, a bait that's a little more dense than the water will sink a little faster if it sits nose-down as opposed to sitting level.
This stuff does all matter to me, we fish straight through NJ winters as long as our water isn't frozen, so we're dealing with water temps where you actually do need to pause the bait for 30 seconds, even longer sometimes. Me personally, I like my jerkbaits to sink as slowly as possible, that seems to get me more bites than one that suspends perfectly or slowly floats.
But the suspending at 7' thing......that means the bait runs at 7 ft and suspends. The only way it will stop sinking and suspend is if the water temp changes at a certain depth.
Posted 12 May 2009 - 02:53 PM
So you don't think that being down 7 ft. and the added pressure make a difference? I wasn't sure if the added pressure in depth would affect the suspending of a jerkbait. Wouldn't more pressure as you get deeper make the water more dense at the same temprature? Its like when you dive in a pool down to the bottom and you can feel the added pressure of the water down the deeper you go.
Posted 13 May 2009 - 11:06 PM
Water can't be compressed. So if you have say a cubic foot of water at surface pressures, you still have a cubic foot of water at 100 ft. If anything, it would compress the lure and make it more dense. What you're feeling when you dive is the gases inside your body being compressed by the added pressure. Notice also that when you dive into deeper water, it's no more or less difficult to move through the water. If the water itself was more dense, it'd be more difficult to move through.
But I don't think The pressure change is a factor at 7 ft.
Edited by clamboni, 13 May 2009 - 11:08 PM.