From Marcum website.
This upgrade is for early versions of the Showdown Fish Finder, like the VPG or Showdown 3.2. If you own a Showdown Troller, 5.6, or 5.6 Dual Beam, no updates are necessary. By having your older Showdown upgraded to the 5.6 Software, you will experience the following benefits:
1. 1 ft. zoom Capability - Compared to the existing 3.2 version or older VPG 2.0, where only 5’ 10’ or 15’ zoom windows can be viewed, you can now adjust in 1 ft. increments within each of the zoom ranges so you key in on exactly the part of the water column you want to view. This is a huge improvement and the most requested feature from the customer feedback we received. This new movable zoom capability is an addition to the existing auto bottom lock zoom feature on the machine.
2. Improved Noise (or interference) Rejection Capability. The 5.6 has an improved noise, or IR filter so that it is much easier to “tune out” other units without affecting your ability to see your jig / fish etc.
3. Surface clutter Elimination – The 5.6 eliminates virtually all surface-clutter feedback, so that bottom detection and digital depth readings are always accurate. The surface clutter phenomenon was the root of what became our most frequently asked question last year about the units’ performance. Existing 3.2 or earlier models, sometimes display the “surface-clutter” as depth, which can be a nuisance and somewhat confusing for many anglers. Technically speaking, there is nothing “wrong” with the machine; however, we wanted to keep this from happening, so that bottom readings and critical sonar information is always correct.
