A little ammo... two points.
1)
I just googled something really quick, so I can't vouch for the PDF that I first looked at. But certainly, if this particular doc is not official, then there are some out there that would be. It's a document named "Guidelines for Remodeling of Public Pools." About half way down the first page is the following bullet point:
- Depth markers must indicate the water depth, accurate to the nearest 6 inches as measured from the
pool floor to the middle of the skimmer opening.
That, I believe, is the industry standard. This is why I pointed out earlier that any reasonable person would conclude that a 6' depth means 6' of water, not wall.
2)
Here's more information that supports my notion.
Minimum Water Depths for Head First Diving From Pool Decks, Starting Blocks, Docks and Similar Low Fixed Platforms
www.health.ny.gov
It discusses safe water depths for diving into a pool. All the numbers are associated with water depth, not anything to do with the distance between deck and bottom of pool.
Your assumption that 6' meant the depth of the water is the correct one. His assertion that it means something else is a lie to cover his mistake.
And as I mentioned, since depth can have multiple meanings in a swimming pool, the fact that the contract doesn't specify
which meaning is the PB's error, not yours. He made two mistakes: he didn't build the pool correctly, and his contract does not adequately protect him from that. It attempts to, as he gave himself a ridiculous 12" margin or error (can you imagine building anything that can be off by 6"!?!). And yet he couldn't even hit that.
You really do have a case. It's just up to you to pursue it or not.