As many of you may or may not know, I am a historian by training. I came across the following.
Before the 20th century, it was considered very bad luck for a ship to sail on a friday.Insurance companies even charged higher rates for vessels leaving port on a friday. In 1864, a wily Scottsman in Liverpool became angry over the extra money he was charged, and decided to explode the old myth once and for all. He commissioned a ship to be built. It’s keel was laid on a friday. The ship was launched on a friday, and was crissened the Friday on a friday. They even found a man named Friday to be Captain. The Scott loaded it with expensive cargo and refused to insure it. The ship sailed for New York on a friday.
The good ship Friday was never seen again.
I would point out a couple of things. First, unless you can provide some proof I doubt very much your assertion about premiums being higher if you sailed on a friday. I’d like to see that. I have read a lot about nautical history and never heard this. If it ever did happen I think it would be very exceptional.
Regarding the particular case I would also like to see some support. It sound pretty UL to me.
I will say that AFAIK the crews could be quite ignorant and superstitious but I doubt the masters took much of that into account. Their sailings were conditioned by tides, weather and other objective conditions. I have never heard of postponing a departure on account of the date. Can you provide some further information on this?
The information from the OP is from the book The Sea Hunters by Clive Cussler. While Cussler is best known for his wonderful adventure books starring Dirk Pitt, this book is a non fiction account of many of his searches for lost shipwrecks around the world. He lead the team that discovered the C.S.S Hunley, the first sub to sink an enemy ship and the C.S.S. Arkansas, the valient confeterate ironclad that took on the entire U.S. Mississippi fleet, among others. While it is true that he has a flair for fictionalizing the actual events surrounding the sinking of the ships, the info above comes from one of the chapters where he is detailing the factual events surrounding the search for the lost ships, not the fictionalized stories of the ships themselves. I consider him a historian of no little note, and view him as a reliable source in his own right, but I’m sure there are other sources out there to back up the OP.