Looks like you and I swopped continents for a while there in 2012...except that my vacation was ridiculously expensive (exchange rate) and I expect that yours was a bit more affordable! I can tell you that my experience w.r.t. languages was similar to yours - I find Dutch easy to read but very difficult to understand when spoken. On the other hand Flemish, as spoken in the Brugge region (of Belgium) is very similar to my native language and quite easy for me to follow.
Delving deeper into the site that I mentioned in my previous post, I came across this in part 2 of the HAL history:
"A note in regards to the spelling of the names of the ships; in 1923 Holland America went from Dutch spelling to English spelling and so the ij became the y. Hence the Rijndam of 1900 was spelled Ryndam after 1923. The Ryndam of 1951 started her life with the Y. Although you will find publications once in a while where this is still muddled up."
I suppose for international marketing HAL (the ever-considerate Dutch!) used the "Y", same as the Dutch sports car maker Spyker, which changed from the original name "Spijker". (Not contradicting your explanation, of course)