NavList:

Here is an excerpt from the regulations for examining masters and mates, published in the Colonial Gazette in August 1845.

What is significant is that a candidate for a 2nd class certificate was required to understand chronometers. For a 1st class certificate  knowledge was required of how to  compare two or more chronometers. This suggests that by 1845 chronometers were in common use. Candidates were required to be competant in both long by chron and long by lunar.

Candidates with exceptional (for the period) knowledge were entitled to have their certificates marked "class 1, extra", presumably a forerunner to the now defunct Extra Masters certificate.

I have also attached a paragraph dealing with withdrawal of certificates. It seems that drunkenness was a problem in those days. On the other hand maybe it is no different to workplace drug testing today.

(From the Gazette of Tuesday.)
hereby given, that, from and after the 1st day of November,
1845, the following arrangements and regulations for examining masters
and mates, in the merchant service, voluntarily offering themselves for
examination, will take effect.
By order of the Lords of the Committee of Privy Council for Trade,
J. G. S. Lefevre, Assistant Secretary.
I.
As to the Boards of Examiners.
1. The boards enumerated in the schedule hereto have voluntarily
undertaken respectively to conduct the examinations hereinafter de-
scribed, according to the arrangements and regulations contained in this
notice, which are subject to any future regulations to be from time to
time made by the Lords of the Committee of Privy Council for Trade,
and published in the London, Edinburgh, and Dublin Gazettes.

2. Each Board of Examiners is to examine all persons who shall ap-
ply, as hereinafter is mentioned, for certificates of qualification as
masters or mates of vessels, and shall grant to such of them as upon ex-
amination shall be found to be properly qualified certificates accordingly,
of the classes following
2nd class.
3rd class.
Masters, 1st class.
2nd class.
3rd class.
1st class.
Mates,

3. The actual examiners are to be members of the said enumerated
boards, or proper persons appointed or employed by the boards respectively.

4. In every case the examination is to be carried on by at least two
examiners, who have had charge of ships or vessels on over-sea voyages.

5. In the examination of the first and second classes, hereinafter de-
scribed, the examiners are to be assisted by a scientific person, compe-
tently acquainted with the theory of navigation and nautical astronomy.

6. Such examination is to comprise the several points, and be subject
to the several conditions hereinafter mentioned.

Conditions and Subjects of Examination.

1. No person is to be examined as a master under 21 years of age, nor
as a mate under 19 years, nor who has not previously served at sea for
not less than six years, as regards an examination for master, and for
not less than four years as regards that for mate.

2. All candidates for examination must produce sufficient evidence of
their ages, and certificates of service and sobriety, general good character
and conduct and particular care is to be taken by the examiners to
satisfy themselves as to the habitual sobriety of the party, previous to
granting him a certificate of fitness to take charge and command of, or
serve as master or mate on board, any vessel.

3. They must be able to write a legible hand, and must understand
the five first rules of arithmetic.

4. They will be examined as to their knowledge of seamanship, of
rigging vessels, stowing holds, &.C., in addition to which those to be ad-
mitted into the lowest class, or class 3rd, must be able to correct the
courses steered by compass for variation, leeway, &c., to work what is
termed a day’s work, to prick off the vessel’s place on a chart, either by
the calculated latitude and longitude, or by the bearings of the land by compass.

5. They must show that they understand the use of the quadrant or
and can observe the sun’s meridian altitude, and therefrom de-
termine the latitude, and are able to work the tides by the age of the
moon, from the known time of high water at the full and change.

6. To be entitled to 2nd-class certificates, candidates must, in addition
to all the foregoing qualifications, be able to ascertain the latitude by
double altitudes of the sun, and by meridian altitudes of the moon, or
of those bright planets or stars, the places of which are given in the
“ Nautical Almanac.’’ They must understand the care and management of
chronometers, and the mode of working out and ascertaining the longi-
tude therefrom and they the must be able to ascertain the variation of
the compass by the azimuth of the sun as well as by the amplitude.

7. To be entitled to a lst-class certificate, candidates will, in addition
to all the foregoing qualifications, undergo a more strict examination as
to their proficiency in navigation and also in seamanship, under the
many difficult circumstances and trying situations to which vessels may
be exposed such as having to erect and to rig jurymasts, when sud-
denly requisite, or to form rafts in case of being stranded, &c., and in
such other cases as call for a higher order of'resources. They must have
a competent acquaintance with plane trigonometry, a general knowledge
of nautical astronomy, including the determination of the latitude by
reduction to the meridian, and of the longitude by lunar observations.

8. They must be acquainted with the mode of ascertaining and ap-
plying the deviation of the compass produced by the local attraction,
which is of so much importance in all vessels, and particularly in those
built of iron or having iron on board in any quantity.
They must be practically acquainted with the mode of comparing two or more chro-
nometers, and of rating them by equal altitudes.

9. They must understand the construction of Mercator charts, so as
to be able to correct any errors they may detect in those they possess,
as well as to insert with precision any new shoals or islands they may
discover, and must be well versed in the mode of laying down the re-
quired course on the chart.

10. They must also possess a knowledge of mercantile book-keeping,
by single entry. of any candidate proving himself to have higher
attainments than the foregoing, such as being well versed in great
circle sailing, spherical trigonometry, marine surveying, and a
more extensive knowledge of astronomy, it is to be noted in his certifi-
cate, and is to entitle him to have “ class 1, extra,” thereon.

VIII. Withdrawal of Certificates.
In case any vessel, the master or mate of which has a certificate,
shall be lost, burnt, stranded, or otherwise damaged, or in case any
master or mate having a certificate shall be charged with having been
drunk at sea, or with having been drunk on board at different times in
harbour, the Board of Examiners nearest the port to which the vessel
belongs, or nearest to the place on the coast of the United Kingdom
where the vessel to which such master or mate belongs shall arrive, or
nearest to where they may be when the complaint is brought forward,
may, if it shall think fit, upon receiving any information or complaint
of the event or occurrence, inquire into the same ; arid if it shall appear
to the Board of Examiners undertaking such inquiry that such loss, burn-
ing, stranding, or damage, &c., of the vessel has been occasioned by the
misconduct or default of such master or mate, or that such master or
mate has been drunk whilst on duty, such Board of Examiners may, if
it shall think fit, withdraw the certificate of such master or mate, and
declare that the same is withdrawn accordingly.