Nice on you for doing the measurements - I wasn't even sure the unit lol. Living in the shadows of chests and tails is the only life for the people here; there's a reason the rest of the world past these girls is uncharted.

tbh I eyeballed it on my phone, but I love doing big girl size calculations! The scale is 300px wide for 150 units, so 2px per unit (I went with km, but miles are probably correct) Both mermaids from head to base of tailfin is ~1100px,so they're 550 km/mil long each!