As far as I know there is no direct commercial equivalent US or Canadian certificate to the RYA Yachtmaster of any variety.
For recreational certification the CYA or Sail
Canada advanced level course is the highest coastal and there is an
offshore level as well which includes some basic Astro.
The ASA was developed in a similar format.
These course have no commercial use except for sailing instructor. I was a CYA instructor but only for the basic level.
Which is roughly equivalent to a Day Skipper.
I’m Canadian so not very familiar with American certification.
The lowest level of STCW certification available in
Canada is a full commercial certificate as a watch keeping officer.
For which command endorsements can be obtained.
There are Canadian Domestic certificate’s for small vessels. Which are commercial licences with restrictions on both area of operation and size of vessel. Right up to unlimited size for the inland waters of the
Great Lakes.
There are no unlimited area licence bellow the MCA equivalent of Class 4, Class 3, Class 2 or Class 1.
I’m not sure but I believe the US system is similar.
There is no Canadian or US equivalent to a RYA Ocean Yachtmaster.
Both Canadian and US commercial certification require much more
documentation of Seatime.
Except for the very lowest levels
If you are Canadian. At this time RYA certification are not recognized for use on a Canadian Vessel.
However
Seatime accrued working on a vessel registered as a yacht in the UK, Dependant territory or
Funny little Islands with an RYA certificate will probably be approved by Transport Canada provided the
documentation meets required TC standard.
Ie must be days not miles.
I doubt if a RYA logbook filled out by the holder will suffice.
The information in it can be transferred to a Canadian Seatime Form. And a Seatime letter.
Which if endorsed by the owner and an owners representative. May be accepted.
Even a Discharge Book requires separate documentation of watch keeping time.