Marine pieces

As you know, in chess composition the composers invent various pieces, which move or capture in various ways.
The IGM Petko Petkov from Bulgaria has written three articles for a group of pieces which have Marine names, and they are published in the site Julia's Fairies by Julia Vysotska from Latvia.

1) Part I – Siren, Triton, Nereid

2) Part II – Poseidon, Marine Knight, Marine Pawn

3) Part III – Scylla, Charybdis