I used this ink for years as Waterman Florida Blue. It's a classic and still in my pen den. Why try to find an equivalent?
I looked at some swabs on the Goulet Pens site and found a few that look pretty close to the Waterman Serenity Blue. I did not see anything in the Diamine lineup that came close.
Personally, I don't find any of them particularly interesting, but that's why there are hundreds of different ink colors...something for everyone!
...Personally, I don't find any of them particularly interesting, but that's why there are hundreds of different ink colors...something for everyone!