solution explanation: you're looking for letters "under the sea," or the letters that are directly beneath the letter C. reading from left to right, these four letters spell out SALT.
Nice first meta. I just now saw this as it was featured this week. My one suggestion would be not to put the 'C's in circles. That made it a bit too easy.
Nice work! One of my first attempts at meta construction, a 15x15 called Sunken Treasure, followed a similar concept: https://crosshare.org/crosswords/taKJAocqUlFpXH8JsItN/sunken-treasure Of course, your puzzle is faster and more straightforward! You may have just inspired me to try constructing a mini! :D
Great little puzzle! When it comes to metas I usually solve the grid and then stare hopelessly at it until I give up finding the meta solution, so it was fun to solve a nice accessible one!