Fishfinder/GPS info

[TNtransplant08]

Hey guys,

Having never purchased one before, I'm in the beginning stages doing research on fishfinder/gps combos. I will probably be waiting until the holidays to purchase one when there may be better deals to be had. So that gives me plenty of time to learn all I can. In the meantime, I thought I'd ask you guys some questions and educate me to speed up the learning curve, so I know what to look for. The reasons for researching a new fish finder are: I'd like to be able to follow along depth contours, see points, old creek beds, etc.; see more details on structure such as rocks, stumps, trees, etc. (my current one is difficult to disinguish between them); see how fish and baitfish are relating to said structure; boat speed and water temp.

1. What are some of the key components to look for?

2. If you had to chose, would you pick one with down scan imaging, side scan imaging, or a graph with more detailed imaging? Black/White vs color? Pros and cons?

3. Do most come with the transductor or is that something you have to purchase seperately? My boat is a simple, aluminum row boat with a trolling motor. Any thoughts on type of transductor and how I could attach to the boat or transom mount motor? I'd like to keep drilling holes to a minimum.

4. What type of batteries do they use and how you attach them to it?

5. What brands you prefer. Seems like most of you prefer either Humminbird or Lowerance. Pros and Cons of the two?

6. I know this has been discussed before, but can you refresh me if you don't mind. What lake maps you prefer for your gps? I recall that there was one that did not have Percy Priest on it. Obviously, the more contour lines the map has, the better.

I think this is a good start for now. I'm sure I'll come up with more questions later as I research. If you have anything else to add, please feel free to do so!

Thanks in advance!
Jamie

[TNtransplant08]

Thought of one more question...What do you think is the ideal wattage is for a depth finder? From what I understand, the higher wattage models are better for deeper water. Don't want one that is more for fishing in 200 feet of water! Also what transductor frequency do you find works best for a variety of depth ranges that you will find on old hickory and percy priest?

[jad2t]

I did a lot of this research too when I recently bought mine. Mine isn't a GPS combo nor does it have DSI but here's a few things I picked up along the way:

Color is nice but it's a waste of money if that's the only thing causing the unit to cost more. If you see big hooks on the screen indicating a fish, what difference does it make whether it's 12 scale monochrome or in pretty colors?

Higher frequency gives better detail due to the way sonar works. Mine has a 20 degree cone with 200kHz and a 60 degree cone with 83kHz. You'll get wider range with lower frequency, less range and higher detail with higher frequency. I like to have mine on split screen so I can see the images from both frequencies at the same time.

I've never seen a unit that doesn't come with a transducer so that shouldn't be an issue.

Battery is easy. A simple 12V battery is all you need. Mine is 12V 8 Amp-hour rated and my depthfinder has a nominal current draw of 350 mA so that means that theoretically on a full charge I should be able to power the unit for 8/0.350 = 22.85 hours. The units that come with GPS and down side imaging, color screens, and all those neat features will draw more current. This is a very small battery I got from Cabelas so storage isn't much of an issue. I actually have it laying in my kayak up in front of my feet.

Do a LOT of reading customer reviews on certain units before you purchase one. Humminbird and Lowrance are great companies but they've both made a unit that turned out to be a dud and you will see nothing but bad reviews on it.

Also pay attention the width of the cone each frequency gives you. With some math a bit more complicated than calculating how long your battery will run the unit, you can estimate the width of the area below the boat that the unit is reading. I'm just learning how to use these myself. Next time I get on the water I'm going to try the 200kHz setting and lower the sensitivity because the screen just gets cluttered. This way I know whatever it picks up is very close to me. With a 20 degree cone below, there is a factor of about 1/3 of the depth. So with that cone scanning, in 20 feet of water, everything I see can be only as far as roughly 7 feet away in any direction. With the 60 degree cone (83 kHz) and in 20 feet of water, the factor is about 1.73 so that means what you're seeing can be up to 34.6 feet away in any direction!! That's obviously harder to locate. These calculations apply to the bottom if you're looking for structure, drop-offs, etc. If you're finding schools of baitfish much shallower, the factor is reduced and they could be much closer.

[Travis C.]

Originally Posted by TNtransplant08

Hey guys,

1. What are some of the key components to look for? If you are using it to navigate to/from your waypoints then screen size is a key component. Otherwise the GPS feature on about all are pretty equal. Sonar on the other hand can vary with strength or quality of display.

2. If you had to chose, would you pick one with down scan imaging, side scan imaging, or a graph with more detailed imaging? Black/White vs color? Pros and cons? It really depends on what you are doing as to whether a side or down would benefit. Obviously both have their place and a combo unit of the two is also great but pricey. Color units are better than black n white when it comes to understanding what is seen on the screen. With a little playing around on the settings you can tell the difference in fish species like catfish or striper for example on a color unit by it's shade of color that is showing up. Also you can easily tell the hardness of items on the bottom or bottom itself easier with color as opposed to thickness of line with black n white models.

3. Do most come with the transductor or is that something you have to purchase seperately? My boat is a simple, aluminum row boat with a trolling motor. Any thoughts on type of transductor and how I could attach to the boat or transom mount motor? I'd like to keep drilling holes to a minimum. Yes most all come with transducers how ever some units the side imagining is an additional cost due to it being a special transducer different than the standard one for that head unit. The only options for not adding holes would be a trolling motor mount or through hull mounted in the base of the hull back next to the drain on the inside of your boat. Usually this option removes the ability to read water temps but in the case of a aluminum boat you may still be able too using a brass setup which may be more trouble/expense.

4. What type of batteries do they use and how you attach them to it?Usually ran off your trolling motor battery or batteries.

5. What brands you prefer. Seems like most of you prefer either Humminbird or Lowerance. Pros and Cons of the two? This gets pretty personal for some people. It's really a preference between those two.

6. I know this has been discussed before, but can you refresh me if you don't mind. What lake maps you prefer for your gps? I recall that there was one that did not have Percy Priest on it. Obviously, the more contour lines the map has, the better.Navionics is most popular and its like looking at a topo map of your lake with more and closer contour lines. Hot Maps is less detail but more fishing oriented with fishing "spots" on the map itself. The maps that come on the HDS units and Lakemaster that can come on the Hummingbirds seem to be a good blend of the two but not sure the cost verses detail over the Navionics. The good thing about the HDS software is you can get a nationwide + coastal setup and you're good anywhere pretty much you'd want to go.

I think this is a good start for now. I'm sure I'll come up with more questions later as I research. If you have anything else to add, please feel free to do so!

Thanks in advance!
Jamie

Biggest thing is to go and look at them and play around with them. Sonar's are the most crucial add on you can get for your boat and you should always get the best one that a budget allows. Going cheap on this piece never ends well and usually gets upgraded within a year.

[MNfisher]

Originally Posted by jad2t

Color is nice but it's a waste of money if that's the only thing causing the unit to cost more. If you see big hooks on the screen indicating a fish, what difference does it make whether it's 12 scale monochrome or in pretty colors?

.

I agree with a lot of what you say Jimmy, except for this statement. I have had both color and no color and I never in a million years would go back to no color. Not only pretty colors, but can really tell the difference in hard and soft bottoms. Also in sun glare, and at night, the color is so much better to see. But that is just my experience.

[Travis C.]

Typically when dealing with cone angles a narrow cone is better for detail in depths and a wide cone is better for coverage up shallow where detail isn't as big of a concern. Example would be trying to see whats on a deep foundation or say one of Old Hickory's submerged locks. A narrow beam will give you far better detail than a wide beam going over that structure. Your window of coverage may be smaller but its a trade off. Then on the other hand up somewhere shallow looking for stake beds a wide beam will help you find them faster than a more concentrated narrow beam.

Usually an auto setting will take care of this but sometimes you need to change it yourself.

[Travis C.]

Regardless which unit you get Jamie, the first thing you do is turn off the fish ID's. They are a joke and completely unreliable. Hummingbird made them popular and the only reason Lowrance has them are old Hummingbird owners complained that Lowrance didn't have them.

The arches are the better method but learn to "read" the arches. Just because there is a big arch and a smaller one doesn't mean they are not equal. How long and where a fish passes under the transducer is a big factor in how it is read. If a 5lb bass is swimming though the outer edge it may be a smaller or same size arch as a 2lb that is stationary directly under the middle of the transducer as you pass over. Heaven forbid a bluegill swims with you under the transducer it will leave you thinking there is the mother of all rockfish under your boat.

Also learn about the "Dead Zone." The cone does not go all the way to the bottom. It is thinnest directly under the transducer and thicker the further away. Fish can actually be there on the bottom but never show on your screen. This is another reason to not use a wide angle over deep water because that will create an even bigger blind spot.

[jad2t]

Originally Posted by Travis C.

Regardless which unit you get Jamie, the first thing you do is turn off the fish ID's.

That's so true! I've read that numerous times and turned mine off the second time out on the water with it.

[Pookie]

For now, I am using a Lowrance HDS-8 at the cockpit with down and side imaging. My fishing partner is running the same, except he has a HDS-7 at the bow as well. I love that unit, but they are not without their faults. 2 things to bear in mind are:

1. Without the map cards, the gps function is useless. I have the Navionics Platinum card, which shows every curve and contour in the lake...in 3D

2. Lowrance customer service absolutely sucks! If there is a problem, you have to send the unit back to California on your dime and are down for approx 2 wks. I have heard that with Hummingbird, you can call them from the boat and they can cure most problems over the phone. If you have to send the unit back to them, it only goes as far as Alabama.

[TNtransplant08]

Thanks for the awesome answers to my questions Travis, Jimmy, Mike, and Pookie. They really cleared up alot of the questions I had and give me things to look for when looking at different fish finders. Based on your comments and other comments made on other websites, I think I will lean towards getting a colored gps. Jimmy made a good point on the black/white, but I think the color contrast will make the detail pop out more and work better in the sunlight, like Mike mentioned. I like the idea of possibly learning how to tell what species of fish the mark might be based on color. While definitely a neat feature, I think I'm leaning towards a fish finder with a graph instead of the Down Scan. I think I'll be able to get a unit with a bigger screen for reading gps for the same price as I would for a downscan unit with a smaller screen. But, who knows, I might change my mind when I see the units in person.

Thanks guys!

[TNtransplant08]

Originally Posted by Travis C.

Biggest thing is to go and look at them and play around with them. Sonar's are the most crucial add on you can get for your boat and you should always get the best one that a budget allows. Going cheap on this piece never ends well and usually gets upgraded within a year.

Great info Travis, I really appreciate the input. It looks like, I'll likely get a trolling motor mount for my transductor. I do remember seeing somewhere about a suction-cup mount. Can you do that for any unit, or is that mostly just for portable ones? Do they come off easy while in the water? Also whats the difference between a normal through the hull transductor and a brass one?

[TNtransplant08]

Originally Posted by Travis C.

Regardless which unit you get Jamie, the first thing you do is turn off the fish ID's. They are a joke and completely unreliable. Hummingbird made them popular and the only reason Lowrance has them are old Hummingbird owners complained that Lowrance didn't have them.

The arches are the better method but learn to "read" the arches. Just because there is a big arch and a smaller one doesn't mean they are not equal. How long and where a fish passes under the transducer is a big factor in how it is read. If a 5lb bass is swimming though the outer edge it may be a smaller or same size arch as a 2lb that is stationary directly under the middle of the transducer as you pass over. Heaven forbid a bluegill swims with you under the transducer it will leave you thinking there is the mother of all rockfish under your boat.

Also learn about the "Dead Zone." The cone does not go all the way to the bottom. It is thinnest directly under the transducer and thicker the further away. Fish can actually be there on the bottom but never show on your screen. This is another reason to not use a wide angle over deep water because that will create an even bigger blind spot.

The fish Id symbol is one reason why I want to upgrade my fishfinder. The one I currently have is a portable one that my stepfather gave to me that was probably made in the late 80's/early 90's. The fish id is all it has and is not reliable. The "fish" could be anything from actual fish, weeds, wood, etc. The only time I can be confident it is fish is when I see a row of fish stacked on top of each other. 95% of the time, its crappie.

Also thanks, for making me aware of the Dead Zone. Didn't even know about that. Do you know of any sites with illustrations of this dead zone?