Reflections on Seamanship

[Palarran]

Wow, Manateeman. Weed is legal here in Michigan too. It's almost 5:00 so give me a minute to catch up. :-)

[Pelagic]

I never considered paranoia when I started this thread.

What i was trying to convey is that the loss of navigational networks and weather routing (however temporary) should NOT be something to fear.

Jackdale's comment to ....'get back in touch with nature' (as an observer), really says it all.

Perhaps because of my early ocean going days both commercially and with yacht deliveries without GPS, you develop and fine tune a sensitivity to your vessels performance as the dynamics of wind and tide dance around you.

Ocean going I was not a slave to celestial as I basically sailed the boat towards a destination and weather predictions from my own observations dominated my thoughts.

If I could not get a fix because of fog or weather, I still had a pretty good feeling of where I was within 50nm

Coastal was more vectors and soundings to keep a safe distance from dangers..

Seamanship is all about developing instincts (or good habits) that will prevent you from making silly mistakes or having a lack of situational awareness.

Think of practicing non electronic navigation the same way you would organise your cockpit or cabin, so that you can find everything in the dark.

Just close your eyes....and visualize!

[GreenWave]

Know what you as an individual can do and not do, same for your crew and your boat


Know the weather and how to assess it


Be Flexible, Patient, and Open to input from others

[CassidyNZ]

Originally Posted by Pelagic

Seamanship is all about developing instincts (or good habits) that will prevent you from making silly mistakes or having a lack of situational awareness.

Quite agree but knowing where you are to the nearest 50nm will see you sail right past most island groups without seeing them

[Pelagic]

Originally Posted by CassidyNZ

Quite agree but knowing where you are to the nearest 50nm will see you sail right past most island groups without seeing them [emoji2]

Agree, but if you are in transit and unable to get a fix for a few days due to weather, you would not be trying to make an island landfall till you got a better position.

[Pelagic]

I don't know the technicalities of defensively turning off GPS, but I am assuming it would be global?

This scenario is what could happen without warning

https://www.scmp.com/news/china/dipl...source=ABS-CBN

[LittleWing77]

Originally Posted by Palarran

Wow, Manateeman. Weed is legal here in Michigan too. It's almost 5:00 so give me a minute to catch up. :-)

+1

[charliehows]

these sorts of discussion always seem to choose such a narrow focus as to make them irrelevant. How does seamanship become whether the gps system has stopped working. If there are any commercial shipping or aircraft functioning there will be good sophisticated nav systems available and , as this covid business has demonstrated, if there are sufficient disruptions to commercial shipping and flight political circumstances will easily overwhelm any other problems people may have moving around the planet. Whats any of this got to do with seamanship?

[Adelie]

Originally Posted by CassidyNZ

Quite agree but knowing where you are to the nearest 50nm will see you sail right past most island groups without seeing them

If the GPS system has gone down, a war has broken out or all of you electronics have failed for whatever reason you are not going to be making for the small low island groups.

That said I would like to keep my positional uncertainty to somewhere in the vicinity of 10nm.

[Rucksta]

Originally Posted by CassidyNZ

Quite agree but knowing where you are to the nearest 50nm will see you sail right past most island groups without seeing them

,

With 50 miles of uncertainty you may not know which island of a group is your landfall.
If you are paying attention you will know it's there.

Some signs to watch.

Con trails.
Cloud formation.
Bird life.
Wave pattern.
Wind shift.
Smell.
Floating debris,

AM/FM radio reception.
VHF traffic.
Cell phone coverage.
Maritime traffic,

Even isolated low lying atolls & reefs make their presence known well out to sea.

[jackdale]

Originally Posted by Pelagic

I don't know the technicalities of defensively turning off GPS, but I am assuming it would be global?

This scenario is what could happen without warning

https://www.scmp.com/news/china/dipl...source=ABS-CBN

GNSS consists of 4 differed systems, GPS, the US version is just one of them.

A lightning strike, electrical fires, etc.. are probably more probable.

The effect of a GNSS failure/shutdown would be more catamorphic for the construction industry than it would be for recreational sailors.

[carstenb]

You really need to differentiate between passages and coastal sailing on this issue. GPS is nice when sailing a passage, but if you have a paper chart and a sextant or the like you can easily navigate a passage.

Coastal on the other hand requires terrestrial navigation skills and a good chart. Many newer sailors have never learned terrestrial navigation.

[Adelie]

Originally Posted by jackdale

GNSS consists of 4 differed systems, GPS, the US version is just one of them.

A lightning strike, electrical fires, etc.. are probably more probable.

The effect of a GNSS failure/shutdown would be more catamorphic for the construction industry than it would be for recreational sailors.

If the US, China or Russia goes to war with one of the other 2, count on those 2 systems being shot down and the remaining systems providing degraded results.

[Hiva Oa]

I have a sextant and just calibrated it yesterday in preparation for 2,300 mile passage.

I love technology too. Dying to get starlink onboard. Sextant and chart is great contrast.

"The sea is selective. Slow in recognition of effort and aptitude, but fast in sinking of the unfit." - Felix Riesenberg

[Dsanduril]

In the bad old days we used to set our passage “arrival” waypoint 20-40 miles upwind/current from the destination. That way when you transitioned to piloting you had room to turn either way in case you were 5 or 10 miles off your intended track.

I still follow that practice today (old habits die hard), although I now start to adjust course one to two days out and the course change is usually minor.

I have been curious how people feel in the current era about making landfall. I still start peering at dawn, trying to find that first hint of land even though nowadays I know exactly where it is on the horizon. When I sail with younger crew they seem to have no anxiety about land showing up where it is expected, and don’t exhibit the same level of anticipation that I have at catching site of land. Don’t know if that’s an accurate observation or just me putting color on something (haven’t discussed it with anyone before this post).