All your questions about reChain.

reChain is an independent service that turns your Garmin inReach into a connection to what matters: marine weather forecasts on a map, an assistant connected to the internet, your route live on a weather map and messaging with family and friends, over the Iridium satellite network. It was created by JCskipper, a professional yacht delivery skipper.

With a Garmin inReach and reChain: you send a request by satellite, reChain sends back a real GRIB file (wind, pressure, waves) as a few short messages, and the free reChain Grib app shows it on a map, offline.

On its own, an inReach sends short messages, shares your position and triggers an SOS. With reChain, it also receives full GRIB weather files, answers your questions through an assistant connected to the internet, and gives the people at home a tracking page with the forecast wind and a way to write to you.

For sailing with reChain, we recommend the inReach Messenger for its price-to-battery ratio: about €300 and up to 28 days of battery life with 10-minute tracking. It is also compact (114 g, 7.8 × 6.4 × 2.3 cm) and waterproof (IPX7), charges over USB-C and can even give your phone a little emergency charge. Above all, it is designed to work with the Garmin Messenger app: you type on your phone's keyboard, which makes it very easy to paste a weather request and copy the GRIB messages you receive into the reChain Grib app. The inReach Messenger Plus adds photos and voice messages, which reChain does not need. Any inReach that can message an email address works with reChain.

Weather and assistant requests are free up to 3 per month, with no account or credit card, then €9 per month for unlimited use, cancel anytime. The tracking page is free. Replies arrive as messages on your Garmin plan and count toward it like any other message.

No. reChain works with the Garmin inReach you already have, with an active satellite subscription. You just add an email contact. Weather and the assistant also work with ZOLEO.

Not on its own: an inReach only exchanges short text messages of up to 160 characters. reChain works around that: the GRIB file is compressed and sent as ordinary satellite messages, and the free reChain Grib app rebuilds the original file on your phone.

Install the free reChain Grib app, draw your area and copy the request it generates. Send it from your inReach to jcskipper.rechain@gmail.com. Within minutes the GRIB arrives as a few messages; paste them into the app to see the forecast.

It depends on the size of the area, the resolution, the forecast range and the data you choose. A typical request uses about 7 to 20 messages. The app shows an estimate before you send, so you can adjust the request.

Any Garmin inReach device that can send a message to an email address: inReach Mini 3 Plus, inReach Mini 2, inReach Messenger Plus, inReach Messenger, GPSMAP 66i and 67i, Montana 700i and 750i, and similar models. ZOLEO communicators are supported for weather too. You need an active satellite subscription.

GRIB files from the GFS and ECMWF models via Saildocs: wind, sea-level pressure and waves, for the area, resolution and forecast range you choose, up to 7 days ahead.

Usually a few minutes after your request is sent. With a poor view of the sky, messages can take longer; the app keeps the messages already received until the file is complete.

Yes. Export the file from the app as GRIB1 or GRIB2 and open it in qtVlm, OpenCPN, Expedition, Adrena or any GRIB-compatible software.

Saildocs is a free email service run by SailMail that sends weather files on request. reChain forwards your request to it, then makes the file small enough to travel through your inReach.

Write your question in a message to jcskipper.rechain@gmail.com, like a text message. Any message that is not a weather request goes to the assistant, which searches the internet and replies in a few short messages starting with “AI reply:”.

Anything internet would help with: engine or electrical troubleshooting, entry formalities, harbour office hours, the general weather situation, the nearest shelter, today's news, a useful phrase to translate for the harbour.

Yes, for 24 hours. You can ask follow-up questions without explaining everything again.

Answers are short summaries, useful to decide quickly. For any safety decision, cross-check with official forecasts and notices, and in distress use your device's SOS button and your distress equipment.

You send them a single link before you leave. They see your track, your last position and the forecast wind around the boat, in any browser, with no account or app.

Yes, from the tracking page, if you have enabled it. The message, up to 160 characters, arrives on your inReach. You can turn this option off at any time.

It updates at the tracking interval set on your inReach; the page reads MapShare every 10 minutes. A gap in the track is usually normal: the device was switched off to save battery or kept inside.

No: tracking is built on Garmin MapShare and works with Garmin inReach devices.

It depends on what you need. For video and remote work, Starlink is the reference. For the essentials (weather, information, position, messages) with very little power and equipment, a Garmin inReach with reChain is a low-power and much cheaper alternative.

A Starlink Mini typically draws 20 to 40 W continuously, and a standard dish more. An inReach runs on its internal battery, rechargeable over USB.

If you mostly need weather, information and messages, yes: a Garmin inReach with reChain uses the same Iridium network, without a €1,074 (Iridium GO!) or €2,148 (GO! exec) device, or a plan of at least €100 a month. The Iridium GO! devices remain better suited if you want voice calls or connected apps.

Yes. reChain sends real GFS or ECMWF GRIB files to a Garmin inReach in 7 to 20 satellite messages, and the free reChain Grib app shows them offline or exports them to your routing software.

No. reChain is not a safety service. Keep your EPIRB or PLB and your DSC VHF. In distress, use them, and your device's SOS button.

No. The Iridium network is recognised by the IMO for GMDSS, but that service runs through a dedicated certified terminal. An inReach uses the same network without being GMDSS equipment; its SOS is handled by Garmin's response centre.

It depends on the model and above all on the tracking interval: from a few days to several weeks. Check your model's specifications with Garmin, and carry a cable and a small power bank.

3 requests per month, weather or assistant, with no account or credit card. The tracking page and messages from shore are free, with no time limit.

Unlimited weather and assistant requests, under a fair-use policy to protect the service. One subscription per inReach address, cancel anytime.

Yes. Replies arrive as ordinary satellite messages and count toward your plan like any other message. A weather file uses about 7 to 20. If you use reChain often, a plan with unlimited messages is the most economical.

At any time from the Manage my subscription page, or from the App Store or Google Play if you subscribed in the app.

No. reChain is an independent service built by JCskipper, a professional yacht delivery skipper. Garmin, inReach and ZOLEO are trademarks of their respective owners.