Coverting Marriott week or points for a cruise.

We've never been on a cruse, can some one give me pointers on exchanging a Marriott week for a cruise as some other member mentioned?

Thank you in advance.

Don't, you are better off paying for a cruise. If you use Marriott points you will still need to pay port charges etc. I have found its better to book a cruise at the cheapest price in the off season and hope for upgrades and deals.