I have finally been able (thanks to a generous poster on YouTube) to watch all 91 episodes of this series, having given up waiting for them all to be released on DVD in Region1. I know that a company called BFS Video released the first 8 episodes on DVD, but that was it. I emailed them to ask why they didn't release the rest, but did not get a reply.
I vaguely recall seeing a few episodes of this series on TV in the 1970's as a kid. I don't know if it was on PBS at the time, because I think there were commercials cut into the programs.
But at long last to be able to see every episode has been a treat. I found the earlier seasons the best and more interesting, but as it wore on to the later seasons, the flaws began to appear. Certain characters (who either got tired of their roles) were written out (or killed off) from the series too hastily and never appeared again. That is the writers fault and leaves unfortunate gap explanations.
But the attention to detail in terms of production design, costumes, and the ship scenes are standard quality for BBC programs during this period. As usual with these British productions during the 70's, they interweave (through editing) studio set videotaped scenes with outdoor filmed sequences, which is a bit annoying at times. Some gaffes here and there with continuity in terms of the characters clothing not matching in some of these spliced-together scenes.
Kudos go to Peter Gilmore who appears in all 91 programs and has to carry the whole series. He did an excellent job. Also to Anne Stallybrass, Howard Lang, Jessica Benton and Mary Webster. The Onedin offspring were not great actors, and I don't recognize them having appeared in subsequent BBC productions.
91 episodes is quite long and probably would never happen today. I used to think the original Upstairs,Downstairs was quite long at 63 parts or Poldark, until this one.
I recommend this series highly especially as I said, the earlier seasons.