In April and May 2020, 180 yachts caught up in Covid-19 border chaos fled across the Atlantic ahead of the Caribbean’s traditional hurricane season.

Most of these vessels carried both an Iridium GO! unit and subscribed to the PredictWind Offshore App. Others had Iridium satellite phones connected to their on-board computers running the PW App.

What is the PredictWind Offshore App?

The PredictWind Offshore App enables vessels to tap into highly detailed weather routes and forecasts, to avoid potentially dangerous weather systems, and to see the location of fellow cruisers wherever they are at sea. It offers weather data based on GRIB files from four different weather models, advanced weather routing, access to the Global Maritime Distress and Safety System (GMDSS), and satellite imagery. Because it is so light on data, it makes a service previously enjoyed only by high-end race boats an accessible must-have for cruisers.

“Behind the scenes, PredictWind’s servers make a staggering billion calculations for each routing on a passage such as the Atlantic, but onboard it’s incredibly simple to use.”

OCC asks PredictWind to support to its 2020 fleet

“Covid-19 made this year’s voyages more complicated,” says Tim Goodyear, who helped to establish the support group for cruisers crossing the Atlantic with the Ocean Cruising Club (OCC). For 2020, in the context of a global pandemic, the number of yachts using the group swelled from an expected 20 boats to an astonishing, estimated 500.

“Usually some boats would stay in the Caribbean, others continue head west through the Panama Canal, and many would head to the Azores before the hurricane season, but there were risks involved in all these options. Most people just wanted to get home to Europe, and that meant changing plans and leaving early. Some arrived in the Caribbean only to leave again almost straight away. Others were about to embark on a multi-year circumnavigation which had to be aborted due to the restrictions. They too needed to get back home.”

But the Ocean Cruising Club would have been remiss to support this fleet without some sort of shore side support, and it strongly recommended the PredictWind Offshore App with Iridium GO! to those making the crossing. Most of the fleet already carried this combination package.

“The PredictWind App paired with the Iridium GO! is an essential tool for those at sea to stay safe and avoid dangerous weather,” says Bryan Hartin, Executive Vice President of Sales & Marketing, Iridium. “Since enabling third party apps in 2015, the Iridium GO! and PredictWind have helped provide incredibly accurate wind and marine forecasts for mariners wherever they sail.”

Getting the best weather route

Tim has high praise for how well PredictWind’s Offshore Weather Routing served him on the crossing too.

His crew of three, plus a dog named Chloe, departed on 29 May aboard the Tayana 48, Mojito.

Mojoto’s track across the Atlantic

To cross check, Tim contracted in a professional weather router to make use of his processing power. “We would typically only use PredictWind, but this passage was particularly complicated with crossing several squally cold fronts.”

As it happened, PredictWind picked up a deepening low developing over the Azores six hours before the professional, land based weather router did.

Mojito had sailed upwind from St Martin for about 16 days, following low pressure systems across the Northern Atlantic, before travelling 400nm to the Southern limits of the iceberg zone to avoid the worst of this low.

“It got bigger and deeper all the time and even with the forewarning we were in 47knot squalls for a while,” says Tim.

The traditional route from the Caribbean to Azores is the same one Christopher Columbus pioneered centuries ago: sail north to Bermuda, with the goal of getting across the light wind patch and into counter-clockwise low pressure systems that will push you east.

But with the advent of weather forecasting and faster boats, many modern sailors will follow the rhumb line – risking large no wind zones but hoping for a light downwind sail all the way there.

While the rhumb line seemed the best option up to the day of departure, PredictWind’s weather route obtained on the day they were to leave supported following in Christopher Columbus’s footsteps and Mojito headed north to hook into low pressure systems.

PredictWind tracking saves the day – many times over

It was important to the OCC that all boats, if possible, used the PredictWind Offshore App with Iridium GO! This was so that skippers could make safer choices in relation to weather. It also meant that they could also see the positions of each of their fellow fleet members and communicate with them via the Iridium GO! Connection. For the shore support team, having the boats thus properly equipped made it possible to keep an eye on the fleet, catch probles as they happened and redirect vessels to assist if needed. Iridium GO! Provided a critical safety feature for the fleet and shore side support.

“The viewing of tracking in the Offshore App is unique. It’s the only solution that allows boats to see other boats' positions while they are offshore, over the connections they already have, we used the Iridium GO! which worked flawlessly,” says Tim. “It enabled us to look after each other, no matter where we were on the route, and without a fast satellite connection.”

When a potential situation was seen on the PredictWind Tracker by the OCC shore team, or one was reported by a member of the fleet to the team, the Tracker combined with the Iridium Go! enabled the OCC shore crew to redirect other vessels to assist or relay distress messages to the Coast Guard’s Maritime Rescue Coordination Centres, who in turn were able to divert commercial ships to the scene. There were numerous occasions where vessels used this feature to get out of trouble: These included two steering failures, three dismastings, one sinking, three significant storm damages, one lightning strike, four collisions with whales, plus other minor incidents such as watermaker failure, fuel shortage, or food shortage. The fact that the Iridium Go! has various communications options made obtaining and providing information remarkably easy. The MRCCs were also very appreciative of the level of detail the shore team were able to provide about each incident.

When distress calls occurred, shore teams were able to see where the boats were, who was nearby and could help coordinate assistance.

How does it look onboard?

“Typically, weather routing has been the domain of racing navigators,” says PredictWind Founder Jon Bilger. “Cruisers had to collect weather data and navigate the old-fashioned way. Until we developed the Offshore App, it was seriously complex and data heavy to get this intel onboard. Our goal was to remove the complexity, to put this power in the hands of cruising customers.”

The navigator presses a button to automatically input his or her vessel’s starting point. Iridium GO! sends this info via satellite to PredictWind’s cloud-based system, where it is processed, returning to the vessel a short time later, as a tiny 10kb package containing four possible routes. Around 50MB of data is processed in the transaction on the PredictWind servers, and it recommends either the fastest or the safest route, enabling the captain to make a call.

Onboard Mojito, Tim Goodyear says that navigation and weather routing with the PredictWind app becomes routine. “Typically, we would check twice a day, 15 minutes after the forecast updates which happen every 12 hours for the models we look at,” says Tim.

Each update provided a weather routing analysis, and a snapshot of wind strengths, gusts, and waves and once they reached the northern iceberg belt, PredictWind also provided all-important information about air temperature.