Fish Finder
Sonar tutorials
Sorry for the long post. I spent an hour trying to find the web reference to no avail. REW provides the following advice on setting up sonars:
About three different things to do to set up depthfinder for the best results.
After trying these things in manual mode - and becoming familiar with the results, you can modify these suggestions to go into a modified auto mode for final on the water use, with excellent results.
1. First find the general water depth over which you are travling.
2. Remember, that any water that is less than about 15 feet will almost never show fish on the graph. The boat and spooking factor is simply too great for fish to stay in the shadow of the boat at depths much shallower than about 15 feet. Once in a while, if you are traveling at a pretty good rate of speed, you might see a fish more shallow, simply because they can't quickly move out of the boats path.
3. Lets say that you are in 15 feet of water.
4. Now, take the depth finder and first insure that all filters are turned off. Many depth finders have surface filters, have rfi filters, have clarifier filters etc. Turn them all off. All of these filters, use a computer interpretation of what should be filtered or what should not be filtered. Use your mind to do the filtering - at least initilally, and become what really needs to be filtered from your display.
5. Now, turn the settings to manual, and the scroll rate to the highest speed.
6. Now, turn the depth setting to a range, which will cover a bit more than double the bottom depth - in other words for a 15 foot bottom depth, at least a 40 or 50 foot range.
7. Now, with the boat sitting still, turn the gain of the depth finder up, until you first see the true bottom at 15 feet, and then see a 2nd bottom reflection at 30 feet. Take note of this gain setting. This is the gain setting that you will want to run the depth finder for this bottom type and depth. At this setting, you will be getting maximum information from your depth finder, with respect to the surface and the initial bottom reading of 15 feet.
8. Now, without changing the gain of the depth finder tun the range to a lower setting like 25 or 30 feet for the given 15 foot lake bottom. Obvioulsy the 2nd bottom will disappear, because it is off scale, but you will be receiving maximum information, with respect to the surface and the 15 foot depth.
9. Again, with the boat standing still, preferably on a calm day, and the motor and all other electronics turned off - take a 1/16th or 1/32 oz jig or split shot, and lower it slowly along side the transducer and lower it slowly to the bottom.
10. The test for your depth finder is your ability to follow this very small piece of lead, all the way from about 2 feet under the depth finder, all the way to the bottom of the lake. It should show up as a line, with a falling angle to the line, which will correspond to the rate at which you drop the jig. At any point, in the jigs descent, if you freeze the drop - the depth finder should simply display a solid black horizontal line moving quickly across the screen.
11. Now, as your jig nears the bottom of the lake, you might lose track of the jig, or it might blur into the bottom reading. If you are on a relatively hard bottom, this bluring, it the distance, above the bottom, where you will be able to reliably mark fish. You might find this distance to be as much as 2 feet or as little as two or three inches. It is quite possible, that if you look very closely, and if you are on a farily hard bottom, you might see a slight thickning of the bottom reading when your jig is only about 2 inches above the bottom. If so, this is the true indication - of where fish can be sensed.
12. Following these tests, you know the best that the depth finder can deliver. Now, you need to test a real world.
13. Turn on all of the other posslible electronics in the boat. Turn on the vhf radio, turn on the trolling motor, turn on the am radio, turn on the fm radio, turn on the gps, turn on the kicker, turn on the big motor. At each of these points, use the lift drop method on the jig, to insure that you can still sense the clear changes in the jigs positon. As long as you can still sense the jigs changes, you will be fine.
14. It is quite likely however, that you might find that turning on one of the other electrical items in the boat - could seriously affect the clear display on your depth finder. Armed with the knowledge of what causes the interference, you can began testing filters.
16. Now, with the knowledge, of how a jig should look, and what effects if any - the other items cause on the display, you can now turn on and off the various filters on the depth finder, to see what, if any effect these have on the display. Now integrate this information into either using thse filters, set in the correct method, to resolve problemes caused by some of the other interfering items in the boat.
17. Finally, when you have learned all of these things and their interaction, you can then duplicate the great action that your unit is capable of displaying, in the auto mode. Turn the unit to auto mode, and do the necessary tweaks in the auto mode, as explained in your users manual to duplicate the display that you found to work so well in the manual diaplay.
Good luck and enjoy a great product.
Take care
REW
About three different things to do to set up depthfinder for the best results.
After trying these things in manual mode - and becoming familiar with the results, you can modify these suggestions to go into a modified auto mode for final on the water use, with excellent results.
1. First find the general water depth over which you are travling.
2. Remember, that any water that is less than about 15 feet will almost never show fish on the graph. The boat and spooking factor is simply too great for fish to stay in the shadow of the boat at depths much shallower than about 15 feet. Once in a while, if you are traveling at a pretty good rate of speed, you might see a fish more shallow, simply because they can't quickly move out of the boats path.
3. Lets say that you are in 15 feet of water.
4. Now, take the depth finder and first insure that all filters are turned off. Many depth finders have surface filters, have rfi filters, have clarifier filters etc. Turn them all off. All of these filters, use a computer interpretation of what should be filtered or what should not be filtered. Use your mind to do the filtering - at least initilally, and become what really needs to be filtered from your display.
5. Now, turn the settings to manual, and the scroll rate to the highest speed.
6. Now, turn the depth setting to a range, which will cover a bit more than double the bottom depth - in other words for a 15 foot bottom depth, at least a 40 or 50 foot range.
7. Now, with the boat sitting still, turn the gain of the depth finder up, until you first see the true bottom at 15 feet, and then see a 2nd bottom reflection at 30 feet. Take note of this gain setting. This is the gain setting that you will want to run the depth finder for this bottom type and depth. At this setting, you will be getting maximum information from your depth finder, with respect to the surface and the initial bottom reading of 15 feet.
8. Now, without changing the gain of the depth finder tun the range to a lower setting like 25 or 30 feet for the given 15 foot lake bottom. Obvioulsy the 2nd bottom will disappear, because it is off scale, but you will be receiving maximum information, with respect to the surface and the 15 foot depth.
9. Again, with the boat standing still, preferably on a calm day, and the motor and all other electronics turned off - take a 1/16th or 1/32 oz jig or split shot, and lower it slowly along side the transducer and lower it slowly to the bottom.
10. The test for your depth finder is your ability to follow this very small piece of lead, all the way from about 2 feet under the depth finder, all the way to the bottom of the lake. It should show up as a line, with a falling angle to the line, which will correspond to the rate at which you drop the jig. At any point, in the jigs descent, if you freeze the drop - the depth finder should simply display a solid black horizontal line moving quickly across the screen.
11. Now, as your jig nears the bottom of the lake, you might lose track of the jig, or it might blur into the bottom reading. If you are on a relatively hard bottom, this bluring, it the distance, above the bottom, where you will be able to reliably mark fish. You might find this distance to be as much as 2 feet or as little as two or three inches. It is quite possible, that if you look very closely, and if you are on a farily hard bottom, you might see a slight thickning of the bottom reading when your jig is only about 2 inches above the bottom. If so, this is the true indication - of where fish can be sensed.
12. Following these tests, you know the best that the depth finder can deliver. Now, you need to test a real world.
13. Turn on all of the other posslible electronics in the boat. Turn on the vhf radio, turn on the trolling motor, turn on the am radio, turn on the fm radio, turn on the gps, turn on the kicker, turn on the big motor. At each of these points, use the lift drop method on the jig, to insure that you can still sense the clear changes in the jigs positon. As long as you can still sense the jigs changes, you will be fine.
14. It is quite likely however, that you might find that turning on one of the other electrical items in the boat - could seriously affect the clear display on your depth finder. Armed with the knowledge of what causes the interference, you can began testing filters.
16. Now, with the knowledge, of how a jig should look, and what effects if any - the other items cause on the display, you can now turn on and off the various filters on the depth finder, to see what, if any effect these have on the display. Now integrate this information into either using thse filters, set in the correct method, to resolve problemes caused by some of the other interfering items in the boat.
17. Finally, when you have learned all of these things and their interaction, you can then duplicate the great action that your unit is capable of displaying, in the auto mode. Turn the unit to auto mode, and do the necessary tweaks in the auto mode, as explained in your users manual to duplicate the display that you found to work so well in the manual diaplay.
Good luck and enjoy a great product.
Take care
REW
Fish Finder
Thanks for the detailed instruction on how we can do this.
CAUTION to the average angler
The only thing worse than having a fishfinder show you too many fish targets is one that doesn`t show you fish..... quite frankly with all the instruction given above I think personally I will leave mine alone..... cause no doubt I would mess something up for sure and spend the whole summer wondering what I am doing wrong.... this lure used to work... this spot used to hold fish.... I used to be good enough to catch fish....
I think that sometimes we get just a tad too technical.... for those that make this work... bravo.... I think there is a Scientific Fishing club out there somewhere.
If you buy a product out of the box and take it home.... do you turn off all the features when you use it..... why would you do it with a finder...
Just my 2 cents.
CAUTION to the average angler
The only thing worse than having a fishfinder show you too many fish targets is one that doesn`t show you fish..... quite frankly with all the instruction given above I think personally I will leave mine alone..... cause no doubt I would mess something up for sure and spend the whole summer wondering what I am doing wrong.... this lure used to work... this spot used to hold fish.... I used to be good enough to catch fish....
I think that sometimes we get just a tad too technical.... for those that make this work... bravo.... I think there is a Scientific Fishing club out there somewhere.
If you buy a product out of the box and take it home.... do you turn off all the features when you use it..... why would you do it with a finder...
Just my 2 cents.
-
Cancatchbass
- Gold Participant
- Posts: 1692
- Joined: Fri Jan 10, 2003 4:30 pm
- Location: 1000 Islands
Unfortunately
Unfortunately, if you do not follow REW's advice there is little likelyhood of ever actually seeing a fish with your unit. You will see lots of fish symbols, surface clutter and various false readings, but fish? You will never know what you are missing.
Leaving your unit in full auto mode as it comes out of the box pretty well relegates it to being a depthfinder.
CCB
Leaving your unit in full auto mode as it comes out of the box pretty well relegates it to being a depthfinder.
CCB
Sonar units
Hi Buster:
Regardless the discussion board, folks usually mean exactly the same thing whether they use the terms fishfinder, depthfinder and/or sonar unit. You shouldn't experience any difficulty setting up your Fishmark 320 for optimal use if you follow the instructions set out by REW. However, one caveat - I haven't read the manual for a Fishmark 320.
Regardless the discussion board, folks usually mean exactly the same thing whether they use the terms fishfinder, depthfinder and/or sonar unit. You shouldn't experience any difficulty setting up your Fishmark 320 for optimal use if you follow the instructions set out by REW. However, one caveat - I haven't read the manual for a Fishmark 320.
Sonar units
Buster:
Theoretically, your friend could be better off. You will recall from REW's remarks that these "filters" are interpreting what the sonar unit sees rather than allowing you to interpret what it sees. On the other side of the coin, he could be worse off if his sonar is adversely impacted by some electrical imcompatibility (noise) from other things on the boat. These so called "filters" can sometimes filter out that "noise".
As well, some fishfinders are designed for almost complete automatic operation. A fishing colleague, who owned a Humminbird 400 (older model), could not turn off Fish ID.
REW's guidelines are quite complete in addressing all issues. You can eliminate and/or at least be aware of all potential interference to the optimal operation of your 320 by following his instructions to the letter, or you can opt to only try and see how close to the bottom you can see your lead jig. It all depends on what you want to know.
Theoretically, your friend could be better off. You will recall from REW's remarks that these "filters" are interpreting what the sonar unit sees rather than allowing you to interpret what it sees. On the other side of the coin, he could be worse off if his sonar is adversely impacted by some electrical imcompatibility (noise) from other things on the boat. These so called "filters" can sometimes filter out that "noise".
As well, some fishfinders are designed for almost complete automatic operation. A fishing colleague, who owned a Humminbird 400 (older model), could not turn off Fish ID.
REW's guidelines are quite complete in addressing all issues. You can eliminate and/or at least be aware of all potential interference to the optimal operation of your 320 by following his instructions to the letter, or you can opt to only try and see how close to the bottom you can see your lead jig. It all depends on what you want to know.
more thoughs
the boomerangs are actually the swim blader of the fish. It has to do with the air in the swim blader that reflects the sonar at a different rate that the solid portion of the fish. ( your fish has to be ralatively still to get a perfect hoop) If you do use the symbols, (which i don't) use common sense. If the fish finder is telling you there are hundreds of fish at 1 to 3 feet directly behind your boat, have a look at the back of your boat under your transducer. I will make an amazing prediction, yup ... no fish there. This is sometimes due to an improperly installed transducer. You are picking up turbulence, or bubble from the water passing under your boat. Your transducer has to be mounted slighly lower than the hull of your boat to get clean undisturbed water.
I have been over a school of walleye where you see 2 or 3 black lines going across your screen. These are moving fish. ( i actually caught 7 of those little guys) The depth is also up for interpretation. The displayed depth is the shallowest part of your cone angle. One side of the boat could be quite a bit deeper than the displayed depth.
Just my 2 cents.
Mark
I have been over a school of walleye where you see 2 or 3 black lines going across your screen. These are moving fish. ( i actually caught 7 of those little guys) The depth is also up for interpretation. The displayed depth is the shallowest part of your cone angle. One side of the boat could be quite a bit deeper than the displayed depth.
Just my 2 cents.
Mark
Fish arches
Miamothe:
My understanding of fish arches is different than yours and consequently is the reason for my post. I believe its important to all of us to properly understand fish arches. You may be interested in reading the article at:
http://www.cabelas.com/information/cabe ... rches.html
The same article appears on the Lowrance site at: http://www.lowrance.com/Tutorials/Sonar ... ial_10.asp
Perhaps, we'll have other comments as well.
My understanding of fish arches is different than yours and consequently is the reason for my post. I believe its important to all of us to properly understand fish arches. You may be interested in reading the article at:
http://www.cabelas.com/information/cabe ... rches.html
The same article appears on the Lowrance site at: http://www.lowrance.com/Tutorials/Sonar ... ial_10.asp
Perhaps, we'll have other comments as well.