I use a housed D700 underwater. This has two issues; low light and particulates in the water that when lit with flash cause an effect called backscatter.
The D700 is not a current model, but has excellent high ISO characteristics and I regularly use ISO 1600 or 2000 to scan a site. The main benefit of high ISO is less flash power...which in turn means less backscatter.
And high ISO means you can shoot with torchlight instead of a flash gun.
An example lit with an Orcalight Seawolf torch:-
https://sketchfab.com/models/3e066c87ca8c44a69ff32b9e55f8d25bAn example lit with underwater flash guns:-
https://sketchfab.com/models/ed5190b32d514bc199cc00d85d4a9b19An example of mixing both. The Abbot self propelled gun and Stalwart are lit with flash. The aircraft and Saracen lit with the Orcalight Seawolf. Four separate dives weeks apart, two divers and two different cameras were combined in this model.
https://sketchfab.com/models/c8743258e47747d8b319391cbbec81ecSo I would say the D700 is fine and has one significant advantage; its not a current camera and in spite of being very capable tool can be bought for a fraction of what the current cameras cost.