I have two Atalantas but I have no idea about their history. I don't think that either has been to sea. One is a Marconi Marine and the other is MWT. Both continue to be very good and very reliable.
I started a thread some years ago on the topic, here:
https://www.vintage-radio.net/forum/...ad.php?t=99826
Compared to some of my vintage broadcast TV kit, it's quite a reasonable size and weight, but as ever with MWT products you do receive you money's worth in metal! As an ex-Marconi employee I can say that the old gag was that Marconi was really a metal-working company that did a bit of electronics, but that's not really a true analysis. They just made things 'properly' and items such as the Atalanta were made to last - unlike today's products.
Best regards,
Paul M