Degree of Tilt for Thru-Hull transducer?

[kmoose]

The deadrise at the bottom of the hull at the stern before the first strake is 18 degrees. Areas towards the direction of the bow will only increase. You want the 20 degree tilt.

[dginge]

Thank you.




QUOTE=kmoose;255447]The deadrise at the bottom of the hull at the stern before the first strake is 18 degrees. Areas towards the direction of the bow will only increase. You want the 20 degree tilt.[/QUOTE]

[hobiekanobie]

I have been meaning to post on here for a few days now.... excuse the ramble but hoping to give as much advise as possible.... I install marine electronics here in South Florida for a living. Primarily most of the work I do is on big sport fishes but I do on occasion work on their tenders and centre consoles too. Centre consoles is where I started out in the field. Primarily I install a lot of garmin and also Furuno. Garmin is very user friendly, kinda like an ipad. Furuno, most of the stuff I install is on a commercial level, radars, autopilots and sonars. ( I also install AV, stereos etc). From a recreational point of view, garmin is by far the way to go and you will definitely get more for your money/ease of use. I currently just upgraded to a 840xs and Airmar B60 transducer on my ‘72 20SF. Gemeco, maker of Airmar actually have an App where you can narrow down what type of transducer is suitable for you needs etc. in the app is also a “tilt” function which will help you figure out your deadrise. (Side note: those of you with iPhones, open up your compass and slide your finger to the left and you will find a level feature.) on my 20SF where I chose to mount my through hull, it was around 17’ so i went with the 20’ element B60. I will attach a diagram from airmar for best suited installation locations - keep in mind that make sure nothing is mounted or penetrates through the hull forward of your transducer location i.e. no through hull fittings or pickups etc. on the bigger boats we typically install the transducers on a fairing block. This lowers the transducer and keeps it below the air pocket. All hulls, particularly stepped hulls, create an airpocket which will not allow the transducer to operate correctly - evidence of this is when backing up, the screen goes fuzzy and cannot give you an accurate depth, depth display blinks. Once the boat is moving forward and the boat passes the turbulent water the transducer will read correctly.
Now, chirp vs traditional......
The big debate.... personally, I prefer a traditional transducer. I find it easier to dial in. What i have seen in the industry is that everyone wants chirp, but 90% of these people that want it have no idea what chirp is, just that it is the latest most techie thing released so to catch fish i have to have it.... I work along side professional boat captains daily that have no idea what chirp is - and this is their job, this is all they are paid to do.... mind boggling.
The simplist difference is that a traditional transducer will ping on a single frequency, be it 50kHz for deep water - upto or around 1200-1800ft depending on KW of transducer or 200kHz for shallow water. There are also some transducers that allow mid range frequencies too.
Chirp will ping on multiple frequencies in a range, allowing for a more definitive image below.
Some quick reading - https://scout.com/outdoors/bass-fish...onar-101451465

I hope this helps some, feel free to contact me if you have any questions or need some advice/guidance etc

[John3325]

That, was an awesome bulk of information. Much appreciated!

[kmoose]

I have both chirp and traditional fixed frequency ducers and one benefit to using chirp with the higher end Garmin MFDs is that you can single select the frequencies within the range of the chirp ducer you select. This allows for some very fine tuning and also allows you to run multiple ducers without conflicting returns.

[hobiekanobie]

Moose, you are absolutely correct. The latest trend now is to install 2 ducers each with a separate GSD26. The last 4 or 5 refits and installations i have done, the most common package is the B275LHW (low, High - Wide) and a R409LWM (Low-Wide, Medium) so now, you have all 3 level chirp frequencies L,M,H and you have a Low wide angle and a high wide angle. Now, this is a lot but keep in mind this is a bigger sport fish, the last boat we refitted, we installed 3x 8622 on the main dash, 2x 7612 on a drop down box from the hard top, 1 8617 in the cockpit and a 8608 in the tower. So this captain has 5 displays on the bridge....
his typical setup was to run the R409 with LW chirp on one display with bottom zoom, and the B275 with HW chirp on the next display with zoom locked at 300ft. The other 8622 was radar and the 2 overhead displays was chart and engine room cameras. So with his setup he is able to run dual frequencies and see what’s happening on the bottom and can then focus on the upper water column. What i did notice with this captain, he would very often switch between chirp and traditional because he was not convinced but was also still learning how to dial it all in. On traditional settings, the B275 High frequency is still Wide, so wether you are using chirp or traditional, the high is wide angle and on the R409, the low on either is wide.

[dginge]

Hobie
Do you feel as if the 8 inch display is enough for a 23 foot sceptre with limited space at the cockpit ? A few people have made comments offline that the 840xs is slow and will frustrate the piss out of you. But they are also raymarine owners. Ha.
I appreciate the write up. Super good info. I looked at the true size demensions between the 840xs and 94sv and it was silly close. I don't want to kill my Helm with limited space but also don't want to get sick trying to read the screen. Ha.
Thanks so much

Originally Posted by hobiekanobie

Moose, you are absolutely correct. The latest trend now is to install 2 ducers each with a separate GSD26. The last 4 or 5 refits and installations i have done, the most common package is the B275LHW (low, High - Wide) and a R409LWM (Low-Wide, Medium) so now, you have all 3 level chirp frequencies L,M,H and you have a Low wide angle and a high wide angle. Now, this is a lot but keep in mind this is a bigger sport fish, the last boat we refitted, we installed 3x 8622 on the main dash, 2x 7612 on a drop down box from the hard top, 1 8617 in the cockpit and a 8608 in the tower. So this captain has 5 displays on the bridge....
his typical setup was to run the R409 with LW chirp on one display with bottom zoom, and the B275 with HW chirp on the next display with zoom locked at 300ft. The other 8622 was radar and the 2 overhead displays was chart and engine room cameras. So with his setup he is able to run dual frequencies and see what’s happening on the bottom and can then focus on the upper water column. What i did notice with this captain, he would very often switch between chirp and traditional because he was not convinced but was also still learning how to dial it all in. On traditional settings, the B275 High frequency is still Wide, so wether you are using chirp or traditional, the high is wide angle and on the R409, the low on either is wide.

[kmoose]

Originally Posted by dginge

Hobie
Do you feel as if the 8 inch display is enough for a 23 foot sceptre with limited space at the cockpit ? A few people have made comments offline that the 840xs is slow and will frustrate the piss out of you. But they are also raymarine owners. Ha.
I appreciate the write up. Super good info. I looked at the true size demensions between the 840xs and 94sv and it was silly close. I don't want to kill my Helm with limited space but also don't want to get sick trying to read the screen. Ha.
Thanks so much

Here is a pic of my dash with a 7610xsv and a 1242xsv. The 8" is a small screen and depending on what you are using it for, size may be a consideration. I will also tell you the 840xs is a pretty dated unit and the feedback you got is likely true if the latest software updates have maxed out the processing power of the unit. The 840 and 1040 are great units but well to the back of the line for continued support from Garmin. That said they still are supporting the unit and provided an update last month.

[dginge]

kmoose
Thank you sir. So would you think the 94sv a better unit? Perhaps I should just get that. I use it for general use. Fish some but ride more with family. I will use split screen when I Snapper fish but hardly ever to locate fish. I use them a lot for general depth and bottom structure when Snapper dropping. I’m going to use the airmar ducer p319. Thanks

Originally Posted by kmoose

Here is a pic of my dash with a 7610xsv and a 1242xsv. The 8" is a small screen and depending on what you are using it for, size may be a consideration. I will also tell you the 840xs is a pretty dated unit and the feedback you got is likely true if the latest software updates have maxed out the processing power of the unit. The 840 and 1040 are great units but well to the back of the line for continued support from Garmin. That said they still are supporting the unit and provided an update last month.

[kmoose]

This is why I try to push folks with limited space towards spending the extra money into the xsv series Garmin MFDs. The internal built sounder has full chirp and traditional inputs as well as 2 separate network ports for radar and a GSD 26. It’s hard to match their flexibility and performance all in one unit.

Considering most SeaCraft owners spend most of their time working coastal depths a GT 51 is an excellent option for bottom fishermen who search for structure but still need want reasonable depth capabilities. The sides scan works great for finding ne bottom and the traditional medium chirp does surprisingly well up to 1000’.