Index error

[Lewis]

Is their an acceptable limit of index error, before you need to adjust to remove or reduce the error rather than just using it to correct on paper?

[Pilot Chris]

The only important point is knowing how much it is, obviously it's good practice to keep it to a min.

[Steve]

Admiralty Manual of Navigation, Volume 2, some old edition, says maximum of 3.0' to be allowed for mathematically and if greater then adjust the sextant.

[Pilot Chris]

Thanks Steve, I guess that's the Admiralty's take on it but mathematically it doesn't matter how big the error is, and although I stand to be corrected I can't remember any max from MCA/IMO etc.

[Silvertop]

Personally I always limited it to 1 degree before adjusting.

[Lewis]

Personally I always limited it to 1 degree before adjusting.

do you mean 1 min, 1 degree seems a lot?

[pignutpilot]

Thanks Steve, I guess that's the Admiralty's take on it but mathematically it doesn't matter how big the error is, and although I stand to be corrected I can't remember any max from MCA/IMO etc.

It's not a requirement to carry a sextant, so the MCA/IMO probably won't set rules for a max error.

[Lewis]

it's not?

[EH75]

Nah a lot of ships don't have them anymore. Lot of my mates in the North Sea for example rarely sailed on boats with sextants. Bit of a pain in the arse when you're trying to learn celestial navigation but then I suppose nights when you get a clear sky in that part of the world are few and far between anyway!

[bobofinga]

It depends on the ships registered trading area weather they need a sextant or not. If its Unlimited than a sextant is required.

The smaller ships in the North Sea are 'Larger European Area' usually so do not need to have one onboard.