Operating Instructions and Installation Instructions
1 
Section 1: Read Me First! 
How this manual can get you out on the road, fast! 
Welcome to the exciting world of digital sonar and GPS! We know 
you're anxious to begin navigating and finding fish, but we have a favor 
to ask. Before you grab the unit and begin installing it, please give us a 
moment or two to explain how our manual can help you get the best 
performance from your compact, wide-screen, combination fish finder 
and mapping GPS receiver. 
First, we want to thank you for buying a Lowrance sonar/GPS unit. 
Whether you're a first time user or a professional fisherman, you'll dis-
cover that your unit is easy to use, yet capable of handling demanding 
navigation and sonar tasks. When you team your unit with our custom 
mapping software MapCreate™, you have an incredible combination. 
You won't find another combination GPS and sonar unit with this 
much power and this many features for this price! 
Our goal for this book is to get you on the water fast, with a minimum 
of fuss. Like you, we'd rather spend more time boating or fishing and 
less time reading the manual! 
So, we designed our book so that you don't have to read the whole thing 
from front to back for the information you want. At the start (or end) of 
each segment, we'll tell you what content is coming up next. If it's a 
concept you're already familiar with, we'll show you how and where to 
skip ahead for the next important topic. We've also made it easy to look 
up any tips you may need from time to time. Here's how: 
The manual is organized into 10 sections. This first section is an intro-
duction to the LMS-520c and LMS-525cDF, sonar and GPS. It tells you 
the basics you need to know before you can make the unit look around 
and tell you where you are, or look below the surface to find some fish. 
Section 2 will help you install your unit, the transducer and the GPS 
antenna module. We'll show you how to get the MultiMedia Card 
(MMC) correctly installed inside the unit. We'll also tell you about some 
of the available accessories. 
Section 3 covers Basic Sonar Operation. It will show you how easy it is 
to run your sonar, right out of the box. This section features a one-page 
Sonar Quick Reference. (If you've already jumped ahead and fig-
ured out how to install the unit yourself, and you just can't wait 
any longer, turn to the Quick Reference on page 55 and head 
for the water!) 










