Obtaining Offshore Weather on Mahi

Obtaining Offshore Weather on Mahi

This month, MAHI is participating in a Cruising “Raft-Up,” or blog hop, hosted by  the CruisingMomBlog.com and Kid4sail.  A Raft-Up is where a variety of Cruising Blogs write about the same topic. This month’s topic is “Weather Aboard.”  

Cruising on a sailboat brings to mind tropical waters and sandy beaches, snorkeling and/or diving, or building sandcastles on the beach.

However, the reality of cruising is you live your lives by the weather-  from closely following every forecast for route planning, or where to anchor, to affecting simple decisions like do you close your hatches before heading to the beach.

Having accurate weather aboard is critical.

Sounds a bit dramatic, but you really do live your life according to weather forecasts.

Right now, we are in the Southern Bahamas,  waiting for favorable weather to travel to Great Inagua, then Jamaica, and Isla Mujeres, near Cancun.  Our plan this year is to end up in Rio Dulce, Guatemala.

So much of our travel and sailing strategies on Mahi are weather dependent.  Weather dictates whether we stay in an uncomfortable anchorage, or decide to move on to somewhere else.  It also determines when we go, including if we have enough wind to sail in the direction we want to go.  

Additionally, the weather and wind affects sea state- which in layman’s terms means how comfortable we will be when we travel on a passage.  Will we also encounter squalls or other unsettled weather?

Waterspout as seen from Mahi

In short, weather is crucial to safety, so on Mahi, we must have reliable ways of receiving accurate forecasts.  This is especially true offshore and on passages, when you are far away from WiFi.  

Here are the ways we receive our offshore forecasts:

PredictWind through the Iridium GO. 

Our PredictWind subscription, combined with our Iridium Go, allows us to download GRIB (Gridded Binary) files for four different forecast models, though we tend to only look at the top two- the Euro and GFS. 

Predictwind screen example

An excellent discussion on the Iridium Go coupled with a PredictWind subscription is found on Sailing Totem’s blog post here.    Behan on Totem talked with me about this method of receiving offshore weather over three years back.    Totem’s positive experience was the reason we purchased our Iridium Go.

Having used it now since Fall, 2015, we completely agree with Totem.  It is worth every penny to receive reliable weather forecasts (as well as make phone calls, send e mail, and text message) out in the middle of no where.

NWS Weather Fax  through Iridium Go

Joe also uses the Iridium Go email to send and receive weather fax information from the National Weather Service that can be displayed on our iPad.  He basically sends a simple code via email through the Iridium Go, then receives back the weather fax data that looks like this:

Sample NWS Weather Fax

Weather fax provides information over and above the PredictWind GRIB files to help us understand not just what is happening with wind and waves, but why.  Joe and I both received training in how to read and interpret weather fax years ago.  In our opinion, more information is better!

Chris Parker Forecasts Through Iridium Go

Iridium Go

We subscribe to Chris Parker‘s weather forecasting emails while we are in the Bahamas and Caribbean.  We receive them in our email through our Iridium Go while offshore.   We also receive them to our regular email accounts when we have wifi.

Again, Chris provides additional forecast details, another interpretation about what we are seeing on both the GFS and Euro.    When we get to the Pacific, we may decide to find a similar service for that geographic region.   It is not essential,  Joe and I use it basically as another set of eyes.

SSB weather forecasts

Icom M600 SSB

Mahi came with an older model SSB, an ICOM M600, which Joe finally got it to work in receive only mode.  We can tune it to pick up weather, including Chris Parker’s Regional reports.  In other geographic areas, we hope to do the research and find other weather information.


These four ways of receiving weather offshore works for our boat.  We love that our primary method, the PredictWind subscription through the Iridium Go, works so well and we rely on the most for safety and life aboard.  Twice a day, we download the latest information, and review it together.

Admittedly, Joe is much better at weather than I am, but I am improving my skills year by year.  We have a rule with weather- we both have to agree on any major passage with regards to route planning, boat safety, and comfort.   Cruising requires partners to work as a cohesive team, and this also holds true for weather.

Weather Books on Mahi

Above are a few of the reference guides we have on our boat related to weather.  Hope this list helps you to know what we refer to regarding weather in general and in certain geographic areas.

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