That's where I'd push back. The fish isn't withheld — it gets the most precise description in the book: two feet longer than the skiff, his sword as long as a baseball bat, his tail the blade of a scythe. We never see it whole because Santiago can't hold it alongside; it's measured in rope, in his back, in what his hands give up.
The only measurement taken on land comes after the sharks. Eighteen feet, nose to tail, by a stranger with a length of line. The village has to put a number on it, and that number is what keeps the ending honest: the greatest thing he ever did was real, and it is still bone waiting for the tide.
Same instinct in your drawing — one small boat, then nothing but line.
