Poseidon Mariner Scales (海闘士スケイル) appreciation post in commemoration of the 30th anniversary of the Saint Seiya anime back in 1989. While not the best arc of the series, it had beautiful backgrounds and a nice seapunk color palette. The battles were underwhelming, though. Compared to the Asgard God Warriors, the Mariners felt underpowered. Only Kraken Isaak and Sea Dragon Kanon had interesting backstories, the rest were mediocre at best. My favorite character was Mermaid Thetis and her relationship with Poseidon/Julian Solo, as it mimics the tale of The Little Mermaid in a way.
Here are some scans of the figure boxes by Bandai, 1988-89.
海皇ポセイドン Sea King Poseidon (Julian Solo)
海馬のバイアン Seahorse Baian
スキュラのイオ Scylla Io
クリュサオルのクリシュナ Chrysaor Krishna
Part 2
Mermaid Thetis