I can remember the first verse, but it is 39 years since I wrote it....and we did have "Satnav" in 1979....it was the old Transit Doppler Satnav system (and my official job title by 1981 was "Satnav Chief"):

The thing about this job I hate
Is working with Rho/3 Pulse/8
As on the graph it gaily plots
Positions in the form of dots
That dance and swim before my eyes
As I slowly start to realise
The course the numbers say we steam
The Satnav puts upon our beam
Half a mile or more, I think
The Bloody Pulse/8 is on the blink


There are I think, without digging it out, another 5 verses, ending with:

So seismic companies be on your guard
The choice is limited, I know it's hard
But if you need results that carry some "weight"
Don't trust your positioning to Bloody Pulse/8



(We would "weight" different positioning and ancillary sensors....Doppler sonar, thermistor, Loran, etc) differently in the ship's INS (Integrated Navigation System) according to their precision and reliability.

But, as I said, it makes little sense to someone who wasn't working on seismic vessels in the late 70s or early 80s.