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!