All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
We do not see that it is permissible to work as a maintenance worker in a boat which carries intoxicants. Maintaining this boat in this case is helping it to continuing the transportation and distribution of intoxicants, and this is helping in sin. Allaah Says (what means): {…but do not help one another in sin and transgression. And fear Allaah. Indeed, Allaah is Severe in punishment.}[Quran 5:2].
In addition to this, entertainment trips include many acts of disobedience like women not wearing Hijab, mixing between men and women, music and so forth; all of which are forbidden matters. Therefore, it is not permissible to work as a maintenance worker aboard this boat except in case of a dire necessity, like when the person can not find any other job and he fears that in case he leaves his job, he will spoil those under his guardianship.
For more benefit, please refer to Fataawa 82250 and 84996.
Allaah Knows best.