The Garmin GSD22 is the latest in a line of black box sounders designed to provide fishfinder data to a number of Garmin chartplotters not equipped with an internal fish finder.
This unit is capable of producing 500-, 1000-, or 2000-watts (RMS) of output power depending on the transducer coupled to the unit.
Garmin GSD22 Black Box Sounder
The GSD22 is housed in a black box that measures 7.6-inches by 6.1-inches with a depth of 3-inches.
This unit will connect to a display via the Garmin Marine Network or the CanNet.
The GSD22 is waterproof to IPX7 standards meaning it could be submerged to 1 meter for 30 minutes without damage.
We tested the GSD22 using both a Garmin 5208 and 5212 multi-function display in a number of different test sessions.
The transducer we used was an Airmar B44V that was installed in our test boat several years ago. This unit is only capable of handling 500 watts of this units 2000 watt capabilities.
When fishing weve used the high frequency mode with good results to depths of approximately 300 feet.
With the low frequency selected weve read bottom returns as deep as 2000 feet at dead stop.
This module is a capable black box that gives Garmin chartplotter units the same sounder qualities and features youd expect to find on a standalone unit.
Here is a split screen view on a Garmin 5212 display screen. On the left you can see the high frequency pulse painted our two deep targets (two red circles) while the low frequency display on the right showed the shallow target with a (single red circle) pronounced fish arch. Even after over a dozen additional passes and a number of manual adjustments we were unable to improve the return.
Standard features include auto and manual depth ranging, zoom, and bottom lock. The unit will also display water temperature and speed when connected to a transducer with these capabilities.
Hitting the menu button from the sonar page lets you adjust the range, gain, frequency, and zoom. A depth line and A-scope are also turned on or off from this menu.
Range and gain can be set automatically or manually. Zoom can be turned off or set to 2x, 4x, bottom lock, or split zoom.
Garmin GSD22 Specifications
| Maximum Power (Watts RMS) | Up to 2000 |
| Frequency (kHz) | 50 / 200 |
| Transducer Used for Test | Airmar B44V |
| Auto Depth Ranging | Yes |
| Manual Depth Ranging | Yes |
| Gain | Auto / Manual |
| Zoom | 2x, 4x, Split |
| Bottom Lock | Yes |
| A-Scope | Yes |
| Shift | No |
| Waterproof | IPX7 |
| Warranty Period (Years) | 1 |
Sounder data can be displayed full screen or in a variety of split screen combinations.
During our testing the GSD22 marked all three of the submerged targets we placed in the water fairly well in auto gain. However, we needed to operate in a dual frequency split screen mode to do so.
Neither high nor low frequency would paint all three targets alone. We tried dozens of passes over our test targets as well as a number of fine tuning adjustments. None of this produced results any better than what we were getting using the unit?s automatic gain settings.
The sonar setup menu lets you adjust the background color, we used white for our testing, turn fish symbols on or off, change scroll speed, turn surface clutter on or off, and set whiteline.
Overall we’d rate the Garmin GSD22 black box sounder good for both presentation and ease of use.