Are you measuring the highest altitude of MJ to say it won't be flooded? Lol
You have to take altitude of its base from the sea level and it looks like it can't take 5m rise in sea level.
Nah, look at the ships in the water, then compare them to the land.
It would take way more than 5m rise to sink this, the cliffs are at least half as tall as the ships, and in some places a lot higher. Those are Marine Battleships, you can tell because they have 6 cannons on each side and 4 masts.
https://onepiece.fandom.com/wiki/Marine_Ships#Battleship
Battleship
While standard Marine ships are average in size, a variant exists that is much larger, known as the
Battleship (軍艦,
Gunkan?).
[1] This ship type is the mainstay of the Marines in the Grand Line, and it is also the one used during a
Buster Call. Battleships are larger than a normal-sized
giant and roughly the size of the super giant
Oars Jr., making the ship class among the largest in the world. These ships are used by higher-ranking Marines, such as Admirals and Vice Admirals.
Battleships have four masts, two with two sails and two with one. Like Standard ships, they have a circular superstructure from which one of the main masts emerges from, but theirs has another level. Another rectangular superstructure is affixed to the stern, which is topped by a tan tower. They have three distinctive triple-barreled guns on their front and sides, which are powerful enough to completely destroy smaller vessels and even obliterate an entire island, though only in groups. In addition to these guns, battleships possess two sets of six large cannons on both sides of their hulls.
"Battleships are larger than a normal-sized giant and roughly the size of the super giant Oars Jr".
These things are MASSIVE, New Marineford's shore is way above sea level. Looks like it was built to withstand tsunamis as well.
Nah it can definitely take a 5m rise, these battleships are massive
Look at the size of these things
...
Yo I forgot they were that big
Holy crap
Massive Chonkers