This is the 11454th most frequent Polish word.
jachcie
"Jachcie" is the locative form of "jachty" (yacht) in Polish, meaning "on the yacht" or "about the yacht."
In this context, 'jachcie' is also in the locative case indicating the location of the cruise's setting.
Marzę o rejsie na luksusowym jachcie.
I dream of a cruise on a luxurious yacht.
Similarly, in this sentence, 'jachcie' uses the locative case to specify the location as 'on the yacht'.
Na jachcie zawsze czuję się swobodnie.
I always feel comfortable on the yacht.
Here, 'jachcie' denotes a location on the yacht, using the locative case.