What is Weather Routing Vs. Vessel Performance Monitoring?

There are two general types of operational weather services provided by weather routing companies: Optimum Ship Routing and Vessel Performance Monitoring

Optimum Ship Routing (Weather Routing)
Optimum ship routing is the art and science of developing the “best route” for a ship based on the existing weather forecasts, ship characteristics, ocean currents and special cargo requirements. For most transits this will mean the minimum transit time that avoids significant risk to the vessel, crew and cargo. Other routing considerations might include passenger comfort, fuel savings or schedule keeping. The goal is not to avoid all adverse weather but to find the best balance to minimize the time of transit and fuel consumption without placing the vessel at risk to weather damage or crew injury…Read more http://oceanweatherservices.com/blog/

All BS.
Some dick head in an office telling you to do a great circle in the middle of the f ing winter. Charters pay, because of sales pitch,

The only guy weather routing a ship should have to bloody well sail on the dam thing.

The art of weather routing is best done by an experienced seaman. Sailing on the ship.
We know more about weather and forecasting than some egg head in an office.

How do I know this. I’ve been weather routed.
I’ve also told weather routers to go piss up a rope and explained why.
Funny then they agreed with me.

Seriously. I would take advice from the Farmers Almanac before I would take it from an ocean router. It will be more reliable.

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I have done both, sailed on the damn thing and routed ships

What now, another El Faro thread?

Weather routing refers to finding the optimum route generally. Strictly speaking the El Faro would have been Hurricane Avoidance (or Tropical Cyclone, TRS etc).


As have the personnel at many weather routing services. In a former life, I hired the head of one of them as an expert witness as he had an unlimited Master’s license, 10+ years sailing, and taught Meteorology at an academy where he was chair of the Marine Transportation Dept.


Avoiding the stuff that kills you is a sub discipline of finding the optimum route, imho. At the very least, it’s an example where using an external routing service would likely have improved the outcome.

Would have taken pressure off the master to satisfy perceived office demands. Of course if this was classic hubris and not bowing to pressure, the master might have told them to pound sand and sailed right into the hurricane as he in fact did.

Perhaps hurricanes should be equipped with AIS.

When I shifted from coast-wise to deep-sea one thing I noticed is the fisherman put a lot more trust in the forecasts than do the deep-sea mariners.

I recall crossing the Gulf of Alaska in the Aleutian freighter en route Seattle with capt Doug one time. He came up to relieve me and asked what’s going on?

I told him the wind had shifted to the SE and was increasing and the barometer was dropping. He told me that in 24 hrs we would be getting our asses kicked. He was right.

A few years later I was again crossing the Gulf of Alaska but this time on a 20 kt container ship. Same situation, wind shift to SE and increasing, barometer dropping.

Capt came up to the wheel house and I told him the situation and added that we were going to be into it later.

He told me I was wrong and proceeded so show me on the surface charts how the lows and fronts were going to move and how we were going to remain in good weather. I thought wow, these guys sure know their stuff!

Of course 24 hrs later we were getting asses kicked.

Lesson here is if they are not fisherman don’t listen to them, unless they show you the upper-air charts. If they are not using upper-air charts likely it’s bullshit.

Thread here: 1993 Storm of the Century marked a milestone in Weather Forecasting


Was the captain gracious about it?

I am happy to take advice from fishermen. Way ahead of routers.
The point here isn’t about the forecast for today and tomorrow.

The point is ocean routing services try to convince you they know what the forecast for the next 10 days is. Which is BS. They are guessing.
They always say the same thing. Do a great circle. If we took there advice we almost always ended up in a big storm.

No one knows weather 10 days out IMHO.

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Simple question.

25 000t geared bulker with timber deck cargo, chartered for 15knots leaving PNW tomorrow for Yokohama.

Ocean router and vessel performance monitors. What’s your recommendations
How’s about grain?

Back in the early days when I first worked with Bob Raguso at Bendix Marine Science Services they had recently tested some early algorithms on an old IBM (1130??) and the algorithms did almost always produced the great circle option… so we never used them. This was back in the day when we hand plotted ship weather reports to analyse wind and sea patterns and used the limited numerical surface forecasts and 500 mb forecasts to predict how these patterns would change over time. The key was to involve the master in a conversation prior to departure on route options and encourage input from the master on the vessel’s particulars including any special requirements.

Ben Franklin, in 1786 noted that “vessels were “sometimes retarded and sometimes forwarded in their voyages by currents at sea”. He knew that ships coming from Falmouth to New York took a fortnight longer than those coming from London to Rhode Island.

Franklin had consulted a Nantucket sea captain regarding this and was told that the cause was the Gulf Stream. (Nantucket captains knew of the Gulf Stream because of the whaling trade.) That same captain marked the stream on a chart along with directions for avoiding it.

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Early on there will be a low tracking southeastward over the eastern NP but later the upper air pattern suggests persistent strong westerlies developing over the western NP 37-50N. What would you do based on the particulars of the bulker in question?

Well I would probably read a synopsis. See where they think the lows will go. Look at the weather chart and see if I agree. Or have doubts.

Initially looks like a route by comp GC N of the Alusians might be a cunning plan. I would put money on getting a beating latter if I went that way.
The first low is a bit of a bummer. But what the hell we don’t wait around.
It changes my first plan which would be get to cape flattery and head south.
Due west for a day. Get behind it.
Then possibly Rhumb line.
Actually more likley I would choose to head for a bit North of midway. Then west then for Yokohama.

Now you can tell me why I am wrong. Odds are though I will have less bad weather and be held back less than by going north.
I am going a bit further. I haven’t figured it out but .the difrence between the GC and rhumb line is about 300 ish miles or a days steaming. I could easily loos that going North.
By heading south I am adding a bit of distance but not a lot and getting less adverse weather. Less current.
So those are my thoughts try convince me to do something else. Partly based on the analysis but mostly based on my best guess what the weather is likley to be at this time of year,
When I get over to the west I best pays attention JIK there’s a nasty bit of tropical weather in the area or developing. Should be avoidable if there is and I won’t be that far south.

Up and over. I’d seriously consider staying north of those lows to stay in more favorable winds. Duck back down between lows well to the west.

Going to lose a lot of time plugging into the westerlies crossing at low latitudes.


I agree with the northern track but of course I don’t know the vessels particulars, especially handing short intervals of possible very rough northwesterlies during the second half of the voyage. The risk to the southern route is that persistent westerly sea and swell will add more weather distance on top of the RL distance.