October 5

[Sa'ar Chasm]

No. "Fen" is an incorrect, proposed plural of "fan" used by people who are living in a dreamworld. It is not a word, it is not correct, and anyone who tells you otherwise is mistaken or lying.

Sounds like they're on rather swampy ground there.

Also, "fen" was used as some sort of contract of "dolphin crewmen", possibly a feminine form, in David Brin's second Uplift trilogy (which I should go add to the Recommended Reading thread).