Question 1

Do you need to add a service provider or can you just use it as is?

Accepted Answer

I appologize in advance to those who understand the following information. But to those new to the world of InReach satellite communications I will try to explain the basics.

The InReach features buit into the GPSMAP 66i are for text and email (no photos) messages to anyone from anywhere on Earth using the Iridium Satellite nexwork. Garmin provides these services for reasonable price plans that can meet every budget from $13/ mth. To $70/mth depending on your expected use of the system. InReach also can provide Remote Tracking which will send your position via the satellites to a unique map page where family and friends can follow your progress. Garmin has two types of plans, each with the multi-level options mentioned above. The Annual Contract plan keeps your InReach active and ready to communicate at all times, like a Cell phone. If you choose this plan you are committed for the first year no matter what your actual usage. After that you  are free to drop the service at any time. They also offer a convenient and flexable Freedom plan that costs a bit more but lets you deactivate the InReach for any months when you won't need it, It costs $24.99 each year plus the first month's cost depending on the level of service you choose. After that first month you may deactivate or activate it on a month to month basis. The only thing to remember is you MUST activate before heading into the backcountry away from Internet access. Activation and deactivation may  only be done on-line. Never from the InReach via the satellites. The satelllites will not accept any messages ( even  SOS) from deactivated units. All InReach services are provided through Garmin via your unique account site. If you choose not to sign up for an InReach communication plan you may use all of the other features of the  GPSMAP 66i. But if you NEVER intend to use the InReach features I would suggest you consider buying the GPSMAP 66st at a lower price but without the capibility to use the InReach communication and SOS services from remote location beyond the cellular range.  As for me, I would spend the extra money for the GPSMAP 66i and keep the option to activate InReach communnications if only to have the ability to contact emergency sercices at the press of an SOS button or to get roadside help from a dead Cell zone. The  plans are flexable and inexpensive and can save your life.

Question 2

How big an sd card can you use ?

Accepted Answer

You can use any size card you want, there are tutorials on how to use 128GB card and we suspect that you can also use 256GB card, big problem is that it must be formatted in Fat32 format which is a very old format, and if you transfer payloads larger than 4 GB in size the files will get corrupted, Fat32 is also very slow, so if you go for the big 256GB card, prepare to take several weeks to upload that many maps, and also prepare for the GPS to take several minutes to read the whole library. 32GB memory stuff they say is absolute rubbish, google it and you will see, if it can be done with 64, it can be done in 66.

Question 3

Can it be run on aa/aaa batteries or does it require the rechargeable pack?

Accepted Answer

Unlike its sister GPS only device, the GPSMAP 66st the InReach added GPSMAP 66i only comes with a built-in rechargable battery which is not accessible by the user. I suspect that this is because the energy requirements needed to push InReach messages far into space to passing Iridium satellites requires a battery with more capacity  than AA batterirs can provide. So, like all InReach models the GPSMAP 66i has an internal lithium battery that is not accessible by the user. When, after many years if service it dies, a replacement can be swapped in by Garmin and the unit resealed to meet the waterproof standard.

Question 4

can you use it for finding ptoperty boundries?

Accepted Answer

The GPSMAP 66 can be used to get a position fix of much greater accuracy than 10-15 feet, which might be useful to you for non-professional surveys. To get this does require extra work on your part. You have to enable RINEX logging on the unit while it is in a fixed position for (ideally) 3 or more hours. Turn off the RINEX logging before moving it. The GPSMAP 66 will save this log file so that you can retrieve it with you computer, and using PC software RTKLIB, you can post-process the log file to derive a position that can be accurate to less than a meter. How accurate the position is will depend on the distance to the nearest "base" station, and other environmental factors.  It isn't a simple procedure, either!  Even if you have your property corner latitudes and longitudes accurately recorded in this fashion, you will still only be able to arrive at them again within the normal operating accuracy of the GPS, and the same goes for boundary lines between points. You will have eliminated some position uncertainty however by doing the RINEX post-processing.

ASIN	B07S5GK8NL
Additional Features	100% Global Iridium® Satellite Network, ABC Sensors, Active Weather, Birdseye Satellite Imagery, Interactive SOS Alerts, Location Sharing, Multi-GNSS Support, Preloaded Topo Maps, Two-Way Messaging, Wikiloc Trails
Are Batteries Included	Yes
Audio Output Mode	Digital
Battery Average Life	16 Hours
Best Sellers Rank	#146,274 in Electronics ( See Top 100 in Electronics ) #158 in Handheld GPS Units
Brand	Garmin
Built-In Media	GPSMAP 66i; Access to Birdseye Satellite Imagery; USB Cable; Carabiner Clip; Documentation
Compatible Devices	Smartphone
Compatible with Vehicle Type	Car
Connectivity Protocol	Bluetooth, Wi-Fi
Connectivity Technology	Bluetooth, ANT+, Wi-Fi
Control Method	Touch
Customer Reviews	4.6 out of 5 stars 751 Reviews
Display Type	Color TFT
Global Trade Identification Number	00753759218737
Human-Interface Input	Buttons
Item Dimensions L x W x H	2.5"L x 1.4"W x 6.4"H
Item Type Name	Handheld GPS
Item Weight	0.08 Pounds
Manufacturer	Garmin
Map Types	Topographical
Memory Storage Capacity	16 GB
Mfr Part Number	010-02088-01
Model Name	GRGPSMAP66I
Model Number	010-02088-01
Mounting Type	Wrist Mount, found in image
Operating System	Android
Resolution	240 x 400
Screen Size	3 Inches
Special Feature	100% Global Iridium® Satellite Network, ABC Sensors, Active Weather, Birdseye Satellite Imagery, Interactive SOS Alerts, Location Sharing, Multi-GNSS Support, Preloaded Topo Maps, Two-Way Messaging, Wikiloc Trails Special Feature 100% Global Iridium® Satellite Network, ABC Sensors, Active Weather, Birdseye Satellite Imagery, Interactive SOS Alerts, Location Sharing, Multi-GNSS Support, Preloaded Topo Maps, Two-Way Messaging, Wikiloc Trails See more
Sport Type	Camping & Hiking
Supported Satellite Navigation System	GPS
Touch Screen Type	Capacitive
UPC	753759218737
Unit Count	1.0 Count
Vehicle Service Type	Car
Warranty Description	1 year limited warranty

Garmin GPSMAP 66i, GPS Handheld and Satellite Communicator, Featuring TopoActive Mapping and inReach Technology

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