This is interesting and kind of horrifying. I don't think there are many islands where someone wouldn't see you for 4.5 years and where you could find sufficient food and water.

The note is in Indonesian, except for the boat's and captain's name.
1: Some of them might be in the Aleutians, though.

True. But then you need fuel to survive the winter.

2: Fair point, but no more easily forgible.

Much more easily forged, it's written in Latin script.
But that wasn't my point. My point is, the crew was, as usual, one Taiwanese officer and nine Indonesian men.

Well...

1. As you all know, of course, the wreckage of the American exploration ship "Jeanette" drifted from near Jeanette Island off NE Siberia (between Wrangel Island and the Anzhus) across the Arctic and was recovered three years later off the southern tip of Greenland, inspiring the entirely Memorable explorer Nansen to begin his famous transarctic drift expedition in Fram.

2. I am not an oceanographer but I would guess it is conceivable that a floating bottle could have been drawn north to the Bering Strait, through the Strait, across the Arctic, down past Greenland and into the Gulf Stream, to wash up on the Irish coast. The timeframe makes sense too. If it had been found only a year after the sinking, that would be a less plausible timeline.

3. Minor quibble - the note is in Bahasa, not Taiwanese.

4. Entirely possible that some dude in Ireland might know someone who can write Bahasa (which is not a difficult or obscure language). I have no idea whether the handwriting and phrasing is convincingly Indonesian.

5. I am not sure why anyone who had been shipwrecked would even send that message. What is the finder supposed to do with it? There's no location - not even the last-known location of the ship, nothing about what happened to the ship. Not even "we are four days' drift south of where we abandoned ship, 500 miles NE of Midway" or something.
Even if you had no idea where you were and you just wanted to send a last message, wouldn't you at least write your names? Or the names and details of loved ones who should be informed? No "give my love to my wife, Mrs Chen of 18 Railway Cuttings, Komodo"?

6. The thing about being in the NE Pacific when you have just abandoned ship 600nm NE of Midway is that there are literally no islands there. Not even atolls. The nearest islands are Hawaii. After that it's the Midway group or the Aleutians. There is a reason why, when you and the rest of your bros in the Kido Butai are trying to sneak up on Hawaii, this is the bit of Pacific you decide to sneak through.

7. Therefore whoever wrote this had crossed, at least, hundreds of miles of ocean, while keeping his bit of paper dry - and also remembering to bring with him in his (boat? liferaft?) a small bottle with a cork and some wax to seal it up with. (It's a pint bottle - an Imperial pint, 568 ml. Do Indonesians buy anything at all in Imperial pint bottles?)

This post has some examples of actual messages from shipwrecks: https://paulbrownuk.medium.com/the-life-and-death-history-of-the-message-in-a-bottle-65e9dc6bf41f

The note was signed by able seaman R. Neel and addressed to Mrs. Abigail Neel in Cardiff, Wales. It read as follows:

"To my wife and children. The Stella is going down as I pen my last words. If I do not survive, go to my brother. Goodbye, my loved ones, goodbye."
...
The message, signed by William Graham, read: "On board the Pacific, from Liverpool to New York. Ship going down. Great confusion on board. Icebergs around on every side. I know I cannot escape. I write the cause of our loss that friends may not live in suspense. The finder of this will please get it published."
...
One typical message was found on the shore near Ulverston, England, in January 1907. In a stout bottle, written on the piece of envelope, were the words: "Finder please give this to relatives of Bertha Magnussam, Wavertree, Liverpool, England." The message was signed: "Love from Hubert, and goodbye."

They might have found the bottle on the island. Having an emergency kit that included a candle and dome matches seems reasonable. When I'm hiking, I'd have that, plus a notebook in a plastic bag.

Update to the post, but it doesn't add much https://www.reddit.com/r/beachcombing/comments/1mb9xa1/message_in_a_bottle_yong_yu_sing_18_update/

(I think the identification of the bottle is wrong BTW. Stella Artois Cidre bottles have a much squarer base and a band around the base of the neck that the bottle in the photo doesn't seem to have. And they have crown caps, not corks... there aren't many bottled drinks that have corks. Wine, obviously, and a few premium beers like Leffe.)

They might have found the bottle on the island.

They might, I suppose. And the cork could have washed up separately and been pressed into use to seal the bottle.

It is a bit convenient that neither the cork nor the bottle are available.

The rubber ducks spilled in the Pacific reached the British isles via the Arctic, but it seems to have taken about ten years.

They're probably riding higher and thus more affected by wind, though.

Much more easily forged, it's written in Latin script.

I did notice that, but you'd still have to have enough knowledge to know that that's the most plausible thing they'd do in such a situation.

I think it's a prank, for the reason articulated by ajay in 6.5. Why would shipwrecked sailors send a message in a bottle without including any useful information -- the date (or number of days since the wreck), their approximate location, or even their names?

The only specifics in the note are the facts that are most widely available -- the name of the ship, the name of the captain, and the approximate date of the wreck.

My guess is it was a sailor on a different ship, bored in the North Atlantic, who heard about the wreck and decided to play a fucked up prank.

16: good point. People send messages in order to have some sort of effect on other people! That's what communication is!

And if this is real, either the captain was one of the three survivors, or he wasn't.

If he was, then he would certainly be able to give a rough idea of their position. Couple of deckhands and the cook, maybe they wouldn't have much of a clue, but the captain would know.

If he wasn't - why write his name in Chinese characters? The ship had a Chinese name and they wrote that out in Latin script. Whoever wrote it clearly knows how to render Chinese words in Latin script. Why not just write "Chen"?
Why write his name at all, come to that? And why only write his surname? (I don't think Taiwanese people normally sign letters with just their surname - do they?)

What if the captain survived but was not fit to write? The note could have been written by a crew member who could copy the captain's name but otherwise could not write Chinese.

I wish I'd taken the original stance that it was a prank so that I could see Ajay's strongest case for it being real. (Then I could decide on the old switcheroo, if I wanted.)

Speaking of ships in trouble, my son just finished a book about a mutiny called The Wager. But I haven't read it.

18 last: Taiwanese boats have their names painted in both Chinese and Latin script (visible on the bow in first OP link). Taiwanese people generally sign physical documents with their personal seal. E-mail signatures and the like have full names; I haven't seen or remembered enough handwritten notes to be sure, but I think they would write their whole name. I can easily imagine non-ROC crew finding it useful to know how to write their captains' names, but even more easily imagine a prankster adding it to the note for a veneer of autheniticity.
In the course of this, I've discovered that the Indonesians have so many in peril on the sea that their media use an abbreviation for them: ABK -- anak buah kapal (boat crew).

I wish I'd taken the original stance that it was a prank so that I could see Ajay's strongest case for it being real.

You've seen it!

The case for this being real has five planks:
Timing and location of the find - coastal Ireland, 2025
Details of the container and contents - glass pint bottle, cork, wax, paper, writing in black marker
Language and wording of the message
Content of the message
Trustworthiness of the reporter

And to conclude that it's real you have to conclude that all four of those are plausible.

The first one seems fine, as I said in 5. The second one is moderately strong given Moby's argument in 8. The third has some possible weirdnesses over language and script used but I'm not really qualified to judge. The fourth is weak. The fifth is, well, it's Reddit.

Yes, Reddit. But if a hoax, I think it likely that the person who turned it in was not part of the hoax. Assuming he really did turn it in. You wouldn't want police to know your name/face if they did some testing and found it was fraudulent.

People are dumb.

That does happen. I'm just trying to think of what is more likely.

The guy who found it has now spoken to Al Jazeera - or, at least, AJ is quoting him. No idea if they met him in person or just emailed him.
He also spoke to the Journal, which unlike AJ took the precaution of checking with the police, who confirmed in the least detailed way possible.

https://www.thejournal.ie/message-in-a-bottle-inis-oirr-taiwan-6776873-Jul2025