With the recent announcement of the 472-479khz spectrum allocation for Canadian amateur use, it is a good idea to apprise yourselves of the specific footnotes to operations on that segment of the band:

Specific excerpt regarding 600m follows:

472 – 479 MARITIME MOBILE 5.79
Amateur 5.80A

5.80A The maximum equivalent isotropically radiated power (e.i.r.p.) of stations in the amateur service using frequencies in the band 472-479 kHz shall not exceed 1 W.
Administrations may increase this limit of e.i.r.p. to 5 W in portions of their territory which are at a distance of over 800 km from the borders of Algeria, Saudi Arabia, Azerbaijan, Bahrain, Belarus, China, Comoros, Djibouti, Egypt, United Arab Emirates, the Russian Federation, Iran (Islamic Republic of), Iraq, Jordan, Kazakhstan, Kuwait, Lebanon, Libya, Morocco, Mauritania, Oman, Uzbekistan, Qatar, Syrian Arab Republic, Kyrgyzstan, Somalia, Sudan, Tunisia, Ukraine and Yemen. In this frequency band, stations in the amateur service shall not cause harmful interference to, or claim protection from, stations of the aeronautical radionavigation service. (WRC-12)

In the maritime mobile service, the frequency 490 kHz is to be used exclusively for the transmission by coast stations of navigational and meteorological warnings and urgent information to ships, by means of narrow-band direct-printing telegraphy. The conditions for use of the frequency 490 kHz are prescribed in Articles 31 and 52. In using the frequency band 415-495 kHz for the aeronautical radionavigation service, administrations are requested to ensure that no harmful interference is caused to the frequency 490 kHz. In using the frequency band 472-479 kHz for the amateur service, administrations shall ensure that no harmful interference is caused to the frequency 490 kHz. (WRC-12)

RAC supplementary info/comments from B. Rawlings VE3QN:

– except perhaps in the far north Arctic – no part of Canada is within 800 km of any of the states listed in 5.80A.

-It may also be worth noting that, with the likely efficiency of the antenna systems the average amateur could deploy at 472 kHz, a power of 40 to 60 Watts or more might have to be fed into the transmission line to emit 5 watts EIRP.

– Finally, we presumably will have to await a re-issue of RBR-4 before we see an official limit on bandwidth allowed in 472 – 479 kHz; however, 1 kHz would seem a fair guess in the meantime.