But I saw that Wikipedia says this:
According to most Ashkenazi rabbis, if a woman is in a place with at least two Jewish men who are not sexually licentious, it is permitted for them to be there together.

Oren, I don’t know what the definition of “sexually licentious” is.
The people joining the voyage are participants doing it as preparation for receiving an international license; they don’t know each other beforehand.
I don’t know about myself whether I’m licentious or not, and all the more so not about others.
Should one assume that someone who wears a kippah is not “sexually licentious”? Or based on Sabbath observance? Or is there some other criterion?

I would be glad to hear the Rabbi’s view regarding the definition of sexually licentious.
I’ll just note that in Haredi society, it is commonly accepted that someone who uses a smartphone, and certainly a phone that is not “filtered,” is defined as sexually licentious. And this is based on rulings of the “great Torah authorities of the generation.”
Presumably the local rabbinic authority has a different definition.

For this matter, “sexually licentious” means someone about whom there is concern that he may come to intercourse. It’s impossible to give a sharp halakhic definition here.

That’s a bit of a strange definition. After all, the difference between someone who is sexually licentious and someone who is not is in a case of two men and one woman. But one man and one woman is prohibited even when he is not sexually licentious.
That means that even in the case of someone who is not sexually licentious, there is concern that he may come to intercourse (since “there is no guardian against sexual transgression”), so how can you say that only someone who is sexually licentious is someone about whom there is concern that he may come to intercourse?

Someone about whom there is concern that he may come to intercourse in the situation under discussion.