We tried to stay in what we thought was the optimal area across a dozen divesites. My shallowest dive was 68', the deepest 90'. There's also good stuff to see below about 40'. Tugboat is a pretty good dive in 20'. We saw seahorses at 40', Turtles in 10', one deeper wreck in 80' etc.
An advanced wreck dive that's deeper is the Superior Producer. Two of the best dives on Curacao are boat dives only, Mushroom Forest and Watamula.
The shorediving is among the easiest I've seen anywhere in the Caribbean, generally sandy beach entries, not a lot of current, a lot of sites have on-site or nearby tank rentals. It's a longer surface swim out the the reef at some locations, but easy to navigate, the reef mostly parallels the shoreline.