Well... the description opf the trip was much nicer than the trip itself.
After arriving to Oman we were waiting on our boat for over 1h before it departured.
It was a long trip but you don't see any amazing coast the view is actually quite boring, the bays have nothing to do with 'fjords' and forget about tranclucent water. The water is super poluted, there are like oily green and yellow spots on it so you don't even feel like jumping in. And for sure you can't see anything when snorkeling. And the worse thing is that the people are throwing away the trash from the boat to the water!
The tour itself was pretty good. The reason this particular tour is cheaper than others is that it did not include alcohol, most others include beer and wine. The tour seemed to be marketed primarily to Russians, we were the only English speakers in the group. Also, note that this tour leaves from Dibba, not Khasab, and does not visit Telegraph island. I recommend the Mussandam peninsula, but I would recommend going for one of the more expensive tours that includes more.