Tails brought to my attention an old artifact in the original Ecco the Dolphin that used to make my head spin. It's a strange shell found in Home Bay that shows up on the sonar map as a dangerous object. I used to think it was some sort of special object that opened up some sort of Easter Egg.
According to Tails it's hex values designate it to be some sort of spike, like you would find in Hard Water and other ice stages. Why would the designers put a one of a kind shell at the beginning of Home Bay that's in a hard to reach corner that the player can't access?

The storm occurs leading Ecco on his quest, the purple shell gets sucked into the vortex with Ecco's pod. When you swim back to the shells location after the storm has occurred you'll find the exit leading to the next level and the shell...

...Sorry folks, after the storm has occured the shell is still there and there is no reason why it was ever put there in the first place other then it was a graphic that didn't fit well, like the mysterious tortoise - a one of a kind sprite that doesn't appear anywhere in the game.
I begged Tails to use his expertise on the Ecco the Dolphin ROM for a hack anyone can apply using a hex editor and a few magic numbers. He told me to go to line 86642 and replace 97 (the shell object) with 0F, 10 or 11. These three magic numbers are different animations from the hidden tortoise sprite.

Why sit and wonder what the stupid shell is for, when you could have a tortoise doing a little dance shaken a little...Well you get the point.