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OWNER’S MANUAL
AND REFERENCE
ZOOM
GPSMAP
230 
®
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© 1999 - 2000 GARMIN Corporation
GARMIN International, Inc.
1200 East 151st Street, Olathe, Kansas  66062, U.S.A.
Tel. 913/397.8200 or 800/800.1020
Fax 913/397.8282
GARMIN (Europe) Ltd.
Unit 5, The Quadrangle, Abbey Park Industrial Estate, Romsey, SO51 9AQ, U.K.
Tel. 44/1794.519944
Fax 44/1794.519222
GARMIN (Asia) Corporation 
No. 68, Jangshu 2nd Road, Shijr, Taipei County, Taiwan
Tel. 886/2.2642.9199
Fax 886/2.2642.9099
All rights reserved. Except as expressly provided herein, no part of this manual may be reproduced, copied, transmitted, disseminated, down-
loaded or stored in any storage medium, for any purpose without prior written consent of GARMIN Corporation. GARMIN Corporation here-
by grants permission to download a single copy of this manual onto a hard drive or other electronic storage medium to be viewed for personal
use, provided that such electronic or printed copy of this manual contains the complete text of this copyright notice and provided further that
any unauthorized commercial distribution of this manual is strictly prohibited.
Information in this manual is subject to change without notice. GARMIN Corporation reserves the right to change or improve its products and
to make changes in the content without obligation to notify any person or organization of such changes. Visit the GARMIN website
(www.garmin.com) for current updates and supplemental information concerning the use and operation of this and other GARMIN products.
GARMIN and GPSMAP 230 are registered trademarks of GARMIN Corporation and may not be used without the express permission of
GARMIN Corporation.
January 2000
Part Number 190-00137-10 Rev. B Printed in Taiwan
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Help us better support you by completing our on-line registration
today! Have the serial number of your GPSMAP 230 handy and con-
nect to our website (www.garmin.com). Look for the Product
Registration link on the Home page.
Why should you register your GPSMAP 230?
•
•
•
Notification of Product Updates
Notification of New Products
Lost or Stolen unit tracking
NOTE: If you have previously registered your GARMIN product pur-
chase using a mail-in registration card, we invite you to re-register
using our NEW on-line system. Many services provided by our new
product registration system are now being automated and re-register-
ing your purchase ensures you the best possible support from
GARMIN.
INTRODUCTION
Foreword
Software Version .4.03 or above
Internal Database Version 2.01   
© Navionics Corporation
G-chartTM cartridge data is copyrighted by Navionics
Corporation  and  GARMIN  Corporation  and  may
not be copied or used for any other purpose with-
out permission.
GARMINTM, G-chartTM, AutoLocateTM, TracBackTM and
PhaseTrac12TM are trademarks of GARMIN Corporation and
may  only  be  used  with  permission.  All  rights 
are reserved.
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INTRODUCTION
Cautions
CAUTION!
The GARMIN GPSMAP 230 has no user-ser-
viceable parts. Should you ever encounter a
problem with your unit, please take it to an
authorized GARMIN dealer for repairs.
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CAUTION
The  GPS  system  is  operated  by  the  United  States  government,  which  is  solely
responsible  for  its  accuracy  and  maintenance.  The  system  is  subject  to  changes
which  could  affect  the  accuracy  and  performance  of  all  GPS  equipment.  Although
the GARMIN GPSMAP 230 is a precision electronic NAVigation AID (NAVAID), any
NAVAID can be misused or misinterpreted and, therefore, become unsafe. 
Use the GPSMAP 230 at your own risk. To reduce the risk of unsafe operation,
carefully review and understand all aspects of this Owner’s Manual—and thoroughly
practice operation using the simulator mode prior to actual use. When in actual use,
carefully  compare  indications  from  the  GPSMAP  230  to  all  available  navigation
sources, including the information from other NAVAIDs, visual sightings, charts, etc.
For safety, always resolve any discrepancies before continuing navigation.
NOTE: This  equipment  generates,  uses,  and  can  radiate  radio  frequency  energy
and, if not installed and used in accordance with the instructions, may cause harmful
interference to radio communications. However, there is no guarantee that interfer-
ence will not occur in a particular installation. If this equipment does cause harmful
interference, the user is encouraged to try to correct the interference by relocating
the equipment or connecting the equipment to a different circuit. Consult an autho-
rized dealer or other qualified technician for additional help if these remedies do not
correct the problem.
This device complies with Part 15 of the FCC limits for class B digital devices for
home or office use. Operation is subject to the following conditions: (1) This device
may not cause harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.
The  GPSMAP 230  contains  no  user-serviceable  parts.  Repairs  should  only  be
made by an authorized service center. Unauthorized repairs or modifications could
void  your  warranty  and  your  authority  to  operate  this  device  under  Part  15 
regulations.
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Designed  for  detailed  electronic  charting  and  simple  operation,  the  GARMIN
GPSMAP 230 is a powerful navigation device that can help guide you in water-
ways around the world:
Precision Performance
• 7” High-contrast 4-level gray LCD screen
• PhaseTrac12TM receiver  tracks  and  uses  up  to  12  satellites  simultaneously 
for fast, accurate positioning
• Differential-Ready— just add the optional GBR 21 beacon receiver for better
than 10-meter accuracy
• Gasketed case for use in exposed locations
Advanced Navigating and Plotting
• 250 alphanumeric waypoints with selectable icons and comments
• Built-in worldwide database usable from 4096 to 64 nm scales
• 20 reversible routes with up to 30 waypoints each
• G-chartTM electronic charting with inland and offshore coverage
• On-screen point-to-point distance and bearing calculations
• TracBackTM route feature which allows you to quickly retrace your track log to
a starting position
• Built-in simulator mode
INTRODUCTION
Capabilities
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INTRODUCTION
Warranty
iv
LIMITED WARRANTY
GARMIN Corporation warrants this product to be free from defects in materials and
manufacture  for  one  year  from  the  date  of  purchase.    GARMIN  will,  at  its  sole
option, repair or replace any components that fail in normal use.  Such repairs or
replacement will be made at no charge to the customer for parts or labor.  The cus-
tomer is, however, responsible for any transportation costs.  This warranty does not
cover failures due to abuse, misuse, accident or unauthorized alteration or repairs.
THE  WARRANTIES  AND  REMEDIES  CONTAINED  HEREIN  ARE  EXCLUSIVE
AND IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED OR STATU-
TORY,  INCLUDING  ANY  LIABILITY  ARISING  UNDER  ANY  WARRANTY  OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, STATUTORY
OR  OTHERWISE.    THIS  WARRANTY  GIVES  YOU  SPECIFIC  LEGAL  RIGHTS,
WHICH MAY VARY FROM STATE TO STATE.
IN  NO  EVENT  SHALL  GARMIN  BE  LIABLE  FOR  ANY  INCIDENTAL,  SPECIAL,
INDIRECT  OR  CONSEQUENTIAL  DAMAGES,  WHETHER  RESULTING  FROM
THE USE, MISUSE, OR INABILITY TO USE THIS PRODUCT OR FROM DEFECTS
IN  THE  PRODUCT.    SOME  STATES  DO  NOT  ALLOW  THE  EXCLUSION  OF
INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATIONS
MAY NOT APPLY TO YOU.
To  obtain  warranty  service,  call  the  GARMIN  Customer  Service  department  (913-
397-8200)  for  a  returned  merchandise  tracking  number.    The  unit  should  be
securely packaged with the tracking number clearly marked on the outside of the
package and sent freight prepaid and insured to a GARMIN warranty service station.
A copy of the original sales receipt is required as the proof of purchase for warranty
repairs.  GARMIN retains the exclusive right to repair or replace the unit or software
or offer a full refund of the purchase price at its sole discretion.  SUCH REMEDY
SHALL BE YOUR SOLE AND EXCLUSIVE REMEDY FOR ANY BREACH OF WAR-
RANTY.
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PREFACE
INTRODUCTION
Preface
Congratulations on choosing one of the most advanced marine navigation sys-
tems available! The GARMIN GPSMAP 230 combines the proven performance of
GARMIN GPS with powerful G-Chart electronic charting for detailed cartography
and plotting wherever you cruise.
To get the most out of your new navigation system, take the time to go through
this operator’s manual and learn the operating procedures for your unit. This man-
ual is broken down into two sections for your convenience.
Getting  Started introduces  you  to  the  GPSMAP  230  and  provides  a  tutorial
that will help you become more familiar with the unit. This part will provide you
with  a  basic  working  knowledge  necessary  to  use  the  unit  to  it’s  fullest
potential. 
The  Reference portion  is  divided  into  sections  that  provide  detailed  instruc-
tions on the advanced features and operations of the GPSMAP 230. This allows
you to concentrate on a specific topic quickly, without reading through entire por-
tions of text that you may not need.
An Appendix section concludes the manual with specific information needed
for custom setup, trouble shooting, and indexing.
WARNING!
The electronic chart is an aid to navigation and is
designed to facilitate the use of authorized govern-
ment charts, not replace them. Only official gov-
ernment charts and notices to mariners contain
all information needed for the safety of naviga-
tion–and, as always, the user is responsible for
their prudent use.
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INTRODUCTION
Packing List
vi
Before  installing  and  getting  started  with  your  unit,  please  check  to  see  that
your  package  includes  the  following  items.  If  any  parts  are  missing,  please  see
your GARMIN dealer immediately.
Standard Package:
• GPSMAP 230 Unit
• External Antenna and 30’ cable
• Power/Data Cable
• Mounting Bracket and Knobs
• Owner’s Manual
• Quick Reference Card
Optional Accessories:
• G-chart Electronic Chart Cartridges
• PC Kit