Dragonfly Pro 7" loses bottom

 Gday all,

Just wondering if anyone could shed some light on why my Dragonfly Pro 7 inch loses bottom on my 3.7m tinny once I go over about 8 knots?

I have it mounted on the starboard side half way between the leg and side, on the flat in between the hull ribs on an adjustable transom mount bracket. 


Thanks in advance

timboon's picture

Posts: 2615

Date Joined: 14/11/10

 Hi there Sidey, Welcome to

Wed, 2018-06-27 11:21

 Hi there Sidey,


Welcome to the forum....


Can you please firstly tell us your views on shark culling, firearm laws, AFL team supported and then perhaps I/we can offer some advice...


And just remember, not everybody is entitled to their opinion!!


Only jokes Justin, welcome again and i'm sure there are some fellas here that run the sounder you've got that will offer help or compare the performance they are achieving.



Swompa's picture

Posts: 2913

Date Joined: 14/10/12

I have a dragonfly and get to

Wed, 2018-06-27 11:36

I have a dragonfly and get to about 10 knots before dropping ground. Mine has been in 4 different spots (high and low) so am keen to see suggestions here.

Sidey's picture

Posts: 4

Date Joined: 05/08/12

 Cheers Timboon, for your

Wed, 2018-06-27 11:46

 Cheers Timboon, for your info I like to shoot hawks and sharks whilst soaring like an eagle, but that is only my opinion haha


Mines on a sea Jay nomad, what are you running Swompa?

JohnF's picture

Posts: 2801

Date Joined: 07/07/10

 Its not the DragonFly, its

Wed, 2018-06-27 12:00

 Its not the DragonFly, its the transdcuer location and aeration down the hull going over the transdcuer face. Drop the transducer deeper and ensure there is nothing in front of it that can cause turbulence. On a small tinny, it is hard to set them up right. 


Boston Whaler 235 Conquest......getting the flogging it was built for.

timboon's picture

Posts: 2615

Date Joined: 14/11/10

 This new member shoots

Wed, 2018-06-27 16:01

 This new member shoots Hawks... Can we have him banned Adam?


As long as its with a semi auto i guess its ok....


There is an old saying, early ripe early rotten....


Like i've said you could be doing worse than a clear pic at 8 knots, plenty have but have a muck around with height like John suggested....



Sidey's picture

Posts: 4

Date Joined: 05/08/12

 Haha dont you worry about

Wed, 2018-06-27 17:44

 Haha dont you worry about what's rotten there old Timbo...I would be more concerned about what shouldnt have been thrown out!

Do you think the angle of the transducer from bow to stern would have much of an effect?

Or just trapped air under the hull is the issue.


hilly9's picture

Posts: 284

Date Joined: 13/10/12

 I found with my dragonfly it

Wed, 2018-06-27 19:23

 I found with my dragonfly it worked best mounted very low. Like a few inches under

Posts: 253

Date Joined: 08/06/15

 Depends on your hull sidey.

Wed, 2018-06-27 21:14

 Depends on your hull sidey. Make sure it's not in line with any strakes and play around with the height. On my boat the edge closest to the motor is abou 2mm below the hull. I have the transducer tilted forward a bit so the signal shoots in front of the boat and returns before you have driven past it. Trial and error mate. Before you know it you'll be soaring like an eagle! 

Sidey's picture

Posts: 4

Date Joined: 05/08/12

 Thanks guys, I will try and

Thu, 2018-06-28 06:39

 Thanks guys, I will try and get it as low as possible. Good to know I just have to play around until its sorted. Maybe the setting might be different from trawling speed to when boat is on a plane. Does everyone usually just keep the units on auto settings?