First, to summarize some details from several other related threads --- I purchased a Garmin echoMAP 75sv in Spring 2016 to create my own lake maps on the water ... works great! In the fall removed the echoMAP from my boat and (temporarily) converted as a portable GPS unit in order to find desirable structure while out on the ice; the side-scan skimmer transducer would definitely not be suitable for hardwater use! I would have ordered the GT8HW-IF ice ducer right away but was informed by Garmin that it would NOT work with my Garmin non-CHIRP sonar. Since I wanted a slightly smaller sonar/charplotter to use on ice as well as on a second smaller boat in the summer (or as a secondary unit on my large boat), I acquired an echoMAP CHIRP 53dv at a reasonable clearout price (the newer models have the 'cv' designation) and the ice transducer. That combination works fine on the ice, the review is below. However, as a test,
I swapped the GT8HW-IF ice ducer out to my (non-CHIRP) echoMAP 75sv and discovered that they actually do work together after all!***Brief initial ON-THE-ICE REVIEW of the Garmin echoMAP CHIRP 53dv sonar/chartplotter with GT8HW-IF transducer***The Garmin Quickdraw Contours mapping feature is great for creating contour maps (on the water) and scouting desired lake structure and marking/returning to waypoints (locations). This review focuses on the sonar performance.
Mounted the units onto an old battery booster pack containing a newer 12V 7ah sealed lead acid (SLA) battery.
Upon first power-up with the ice transducer connected, select '
Settings - My Vessel - Transducer Type - GT8HW'.
Reduced the backlight for operation inside the shanty ... '
Settings - System - Display - Backlight - 60%' with continuous day mode '
Settings - System - Display - Color Mode - Day'.
Had the line in the same (9" diameter) hole as the transducer, ice thickness about 30 inches. Noticed some undesirable returns with the transducer touching the side of the ice or very high up in the hole, so re-positioned it to about 2 feet depth and ever-so-slightly away from the sides for a reasonably clear 'view' down through the water column.
Targeting walleye and perch, I prefer the '
Sonar - Split Zoom' display with 5-ft bottom lock on left (press '
MENU - Span - 5ft') and full water column on the right. On the bottom lock (BL) display, zero (0) denotes the lake bottom. Pressing the
[+] button increases the zoom range; from the 5 ft zoom, one press increases to 10 ft, then each subsequent press increases an additional 10 feet ... such as 5 - 10 -2 0 - 30 - 40 - etc. Pressing the
[-] button reduces the zoom, eventually down to the minimum 5 foot zoom.
It seems that whenever the unit is powered off/on, the '
MENU - Gain' reverts back to one of the 'Auto' levels (
Auto Low,
Auto Med or
Auto High). Changed the gain to manual setting around 45% or so for the particular depth ('
MENU - Gain', press the up or down scroll arrow to enter manual mode, then scroll left to reduce the level percentage'); it's just a minor inconvenience to have to do every time, if necessary.
Two frequencies are available for selection in the corresponding '
MENU - Frequency' section ... "
CHIRP" or "
200 kHz". In the conditions tested, I felt the 200 kHz frequency setting provided a cleaner return than CHIRP (tried various gain settings); the depth displayed was slightly different as well ... see the screenshots below. The lure is just over a foot off bottom; the mass of returns between the depths of 5 and 10 ft is a school of baitfish passing by.
200 kHz below
CHIRP below
Below is a screenshot showing what may have been a closely knit group of curious yet non-feeding small walleyes ... didn't even get a nibble out of that! Notice the brief depth change when I jigged the lure ... a very thin layer of ice had formed at the top of the hole and the line movement had caused the transducer float to move slightly.
Works fine so far. Haven't yet been out for a long enough stretch to comment on the power consumption / battery life. Questions? ... Comments? ... Let's hear 'em.
