Wayne P.

Excellent questions. The HDSI transducer produces a thinner Imaging pulse. That thinner pulse covers less area per pulse (ping) so the detail is "finer" or less blurry than a thicker pulse. The depth has nothing to do with it, ONLY the coverage per pulse. The SI and DI is the exact same thing with the Side Imaging units. SI units use the two SI pulses to create the DI view via software by blending the two SI images. A DI (Down Imaging) unit uses a transducer that has a single dedicated downward focused pulse. 2D sonar is the same with both the Compact SI and HDSI transducers--same diameter crystal, same frequencies, and same spec coverage. ONLY the SI crystals are different and only in their lengths.

ALL Humminbird Side Imaging (SI) units do Side Imaging, Down Imaging, 2D sonar and GPS/mapping. The dual view DI/2D screen shot in post #84 is from a Humminbird 798ci SI Combo ----Side Imaging unit. You get that with any Side Imaging transducer.

The Helix 5 SI GPS unit comes with the Compact SI transducer XNT 9 SI 180 T The HDSI transducer is the XHS 9 HDSI 180 T. The HDSI is 2" longer and has longer Imaging crystals.

Take a chisel or screwdrive and chip away all the excess epoxy from around the transducer. Put a piece of wood against the side of it and whack it with a hammer. It should pop loose.

The screen shot in post #79 is with the Compact SI transducer. This is the same unit with the HDSI transducer----notice any difference in image sharpness?

A sharper image is better regardless of screen size.

They have been posted a few times in this thread. I don't have to repeat them. You figure it out.

If you base your position on facts instead of "thinking" and "feeling", that should determine your participation.

I agree, just bought another one for testing. Will be doing that tomorrow. There is already another one not in view that is behind the big screen at the console. You can't have too much information.

I purchase a Side Imaging unit for the Side Imaging feature-the other stuff is very secondary. Yes, a taller display will do better for Down Imaging and 2D sonar as individual views. But combine them in a dual view, this is what the 798 does. For the 798: Chart/2D and Chart/DI are side by side. Chart/SI is one above the other. Your anticipated use should determine which screen layout/ shape you prefer. The 798ci SI Combo has been discontinued for over 3 years. The 798ci HD SI Combo was discontinued at the end of 2013. The both 798's can share data with other units, the Helix cannot The 798's have dual card readers, the Helix has one The 798's have 3 short cut buttons for favorite views, the Helix has none.

A Humminbird 5" square screen is 3.625" wide--that is the 500 and 700 series SI units. The Humminbird Helix 5" rectangular screen is 4.25" wide The Humminbird 800 series 7" rectangular screen is 6.125" wide The Humminbird 900 series 8" rectangular screen is 6.875" wide The Humminbird 1100 series 10.4" rectangular screen is 8.375" wide

The concept is simple, BIGGER is better for a Side Imaging unit. That is because the size of displayed subjects is based on the SI RANGE setting, not the depth like Down Imaging and 2D sonar is. In a 5" unit, the Helix 5 is better than a square screen or the narrow vertical screen of the 698ci HD SI due to screen WIDTH. Side Imaging scrolls across the display from top to bottom using the WIDTH of the screen to display subjects. This is Side Imaging showing 100' of coverage left to right on a 5" square screen: The physical screen dimensions are 3.625" X 3.625" The Helix display is 2.5" X 4.25"

If the unit you are considering has a usage timer, find out the hours and divide that by 8. That will give you an estimated days of use. 600 hours is only 75 days. Look for a well cared for unit that is not left on the boat. My units are not on the boat between the lake and home. At home they are still not on the boat. Actually, right now I have 4 units within reach of my computer.

Navionics has had micro-SD map cards since 2010. Lakemaster has annual issues of maps and they are released at the beginning of each year. This is the first year for the Helix and microSD Lakemaster.

No, the Helix 5 s a better unit for Side Imaging and the 688 is better for Down Imaging and 2D sonar. Screen WIDTH for Side Imaging, screen HEIGHT for the other technologies.

I went today, got there at 10:00 when they opened and left about 3:30. Nothing special over last year. I just talked to a lot of people. Got an Eliminator from Robbie Patterson (Propeller Dyamics) for my trolling motor. Stop by and check them out. Take the time to go to the Navionics seminar. Thomas Harris did a good job with his presentation. Sit up close to the front so you hear everything and can see his Lowrance unit part.

My stuff is mounted like this on my tin can. The big units have RAM mounts. The small one has its own quick disconnect mount. I don't have my units on the boat between home and the launch ramp.

I look for shad schools that have bass with them that are actively feeding. Look at my post #125 here: http://www.bassresource.com/bass-fishing-forums/topic/127481-screenshots/page-9 I posted that to help you with exactly what you were doing.

Good job of explaining what SI is showing. If you want to really sharpen the images, you can use the HDSI transducer instead. Sort of expensive though.

My solution is the picture to the left.

If it is a Side Imaging transducer you get the left side displayed on the right side and the right side displayed on the left side. Hank Parker had a XTM 9 SI 180 T attached backwards on his trolling motor a few years ago and didn't seem to notice the difference. When I saw that, I sent him a message about it and he never responded. I know how to install one, I have one that I don't use anymore. I wasn't unaware enough to attach it backwards. I copied this picture of a SI and a DI trolling motor puck installed.

Every where, especially on the inside and outside grass edges on the ledges.

With a gimble mount unit, that is why some add a RAM or other mount to make dismounting simpler and easier and gives more flexibility for display position. Lots of choics for a quick disconnect mount. RAM Balzout Johnny Ray more

Don't leave your Traps or Spots at home. They get the job done also. A Royal Shad colored Super Spot is a top producer before the grass gets matted.

That is the main creek channel of a man made reservoir. The upper left side shows sort of a swirled bottom, but that was due to me changing the boat direction to criss-cross that channel. The upper side of the channel on the right side is shadowed (horizontal) since sonar cannot "see" around corners. Just indicates the steep dropoff into the channel bottom. The dark streaks at the lower right are the shadows of the fish in the channel. I was actually there that day to record sonar logs for improving the contour map data for that lake. After I saw those fish, I stopped recording and did some catching before continuing logging. Traveling in a straight line with a creek channel changing directions, looks like this: