I thought I had all the basics planned out for our vacation next November. Then I asked my 4 year old what he wanted to do. I guess I should have said while in Disney. His response "lets go to the beach mommy and swim in the ocean" he is now obsessed with the idea

So now I'm tossing around the idea of a cruise. DH is not onboard

and I know nothing about cruising so I'm not sure what to choose. Any tips on why we should cruise and skip the World? TIA
Lots! We cruise a couple of times a year and hit the parks about once a year. While at the parks, we love the experiences more than the rides (I.e. Shows and the slow rides like backlot tour). With that in mind, we really prefer the cruises.
On the cruise, you will find a much more personal experience. For example, we were walking down the hall and ran into Peter Pan. My shy 5 yo quickly hid behind me, however Peter stopped and got down on his knees to talk with DS. After spending about a minute talking, DS and Peter posed for a great picture and on our way back, DS said I forgot that Peter Pan was my favorite character (which he isn't usually). I have had 4 or 5 similar experiences on the boats, but never something anywhere close in the parks.
You will also find the cruise ships more relaxing. While you may walk a lot all over the ship, you are never far from your room if you need something and most kids spend some time in the kids club, giving you time for yourself.
Activities on the boat range in variety, but they give similar Disney like experiences, such as animation classes, Disney Junior experiences, etc. The evening shows are near broadway caliber and tug at the heart strings for both kids and adults.
The best part for us is
Castaway Cay! We love the day at the beach with all the food, ice cream, and drinks just steps away. The beaches are great, the waters are warm and calm, and they have slides and platforms for the kids to play on.
I hope that helps, but I would also pose your question on the
Disney Cruise Forum.