Hello, just pinging this thread in case something new has emerged during the last 6-7 years. Currently the Internet is still divided for the date of the loss between 18, 19 and 20 March.
https://mass.cultureelerfgoed.nl/protinus-ijm85 shows a location NW of Dogger Bank for the loss. In this location, a German air attack is far more probable than an Allied one, especially as the aircraft turned around the ship before an attack (no possible confusion with an U-Boote).
Also the fact that the Luftwaffe reported an attack on a French trawler is probably due to the fact that Dutch and French flags use the same colors, respectively horizontally and verticaly.
The names of the four casualties are listed in this article:
https://www.delpher.nl/nl/kranten/vi...earch=Protinus. I hoped genealy websites may help with the death date, but the master, Klaas Wijker, is listed to have died on 15th March at
https://www.genealogieonline.nl/fr/g...raam/I8724.php....
Found also one wounded, death date listed as 23 March:
https://oorlogsslachtoffersijmond.nl...etrus-voorting
The article below, dated on 1 April 1940, describes with details what happens and gives the date and hour of the attack as 20 March, 1730 hrs. The article where a mine is evoqued was IMHO written before, when the ships was still missing. You can see one such article listed with the
www.genealogieonline.nl webpage above where the whole crew is listed as missing, while we know there were survivors, so my guess is that this article was written before the loss and the news that there were survivors. As HMS Unity returned to base from her patrol on 30 March, it is probable that it was only on this date or the day after that the news were given, so explaining the article in the DUtch newspapers on 1 April.
By the way the death dates on
www.genealogieonline.nl after a new search:
Klaas (Jacobsz) Wijker: three pages, one says 15 March, two 20 March
Gerardus Petrus Voorting: 24 March (above link says 23)
No trace of the other casualties.
As for the Unity rescuing the shipwrecked on 25 March after 6 days, an explanation might be that this was the 6th day they were on their lifeboat (20-21-22-23-24-25) especially as the survivors and the rescuers did not speak the same language, hence the confusion in report.
Why the date of 18 March appears in so many documents I have no idea, but it seems to me that sources from 1940 (Luftwaffe reports, Dutch article) point to 20 March being the right date.