Definitely worth it! Booked my seven year old granddaughter on it last year and she loved it. It's from 9:30-11:30 so the parents get two hours to themselves. I suggest you get to the Grand Floridian marina right at 9:00 when they first open up. Check in your children and then have them pose on the empty dock with Cinderella's castle in the background and their bandanna's on (provided by Disney). Within fifteen minutes, there will be lots of other potential pirates around but you'll have everything squared away before then. All the kids have to wear life jackets and the Cast Members will check for fit - you fit your child yourself.
Each child will be paired with another - in your case, if you have two, they will be together. They have to stay together for the entire cruise. About 9:25, all the kids are gathered together and the adults are nearby. Then the kids are taken onto the boat (it's a pontoon boat with a Jolly Roger on the back). You can easily see the loading process and take lots of pictures. The boat will leave exactly at 9:30. Parents are then free to do whatever they want until 11:30 when the boat will be back exactly at that time.
When you check your children in, you will be given a receipt and a beeper in case of emergencies. You have to have BOTH to get the children back. No child will be taken off the boat until the Cast Member has collected the beeper and the receipt. Again, you can clearly see the unloading process. Extremely safe. I thought my daughter-in-law would combust when she realized her daughter would be going off with "strangers" but the entire process is so carefree, she relaxed immediately.
The kids get a bag lunch of Uncrustables PB&J (you have to indicate any allergies when you sign them in - my granddaughter got grape and not cherry), gummy worms, and a drink. Needless to say, most of that went uneaten since she was so excited about the whole trip. They also get a chest full of cheap trinkets that, of course, they all loved.
Make sure you are there about 11:15 so you get "serenaded" by the returning pirates. If you have a video camera, you won't want to miss it.
My daughter-in-law and I took a complete monorail trip around to all the resorts and visited them for the two hours. My husband and son went over to Animal Kingdom and got Safari Fast Passes for later.
Oh - and one more thing. Don't make the mistake my daughter-in-law almost made. Make sure there's a potty break before the kids get on the boat.
Your kids will really enjoy themselves.