Overview
This is a ranking of the tallest cruise ships, based on the height of the ship above the waterline.The rankings are dominated by the Oasis-class cruise ships followed by the Royal- and Excellence-class cruise ships.
Most of the numbers are based on figures reported in various Wikipedia pages. So, it's as broad and useful a dataset as I can compile, attributed to Wikipedia. May you find something useful here. 
Interactive Chart
Top 30 ranks, by height above waterline in descending order ( rank and segment full dataset - 62 items )
More..
My other lists on Cruise Ships
Largest | Widest | Tallest | Longest Cruise Ships
Builders who created these sea-dominating engineering marvels
Different classes of cruise ships and different cruise lines
Cruise ships with the most state rooms and the largest passenger capacities
The largest cruise lines by passenger count | market share by revenue
Recommended Comparison
Titanic of 1912 vs Symphony of the Seas of 2020