Spa Fitter
Caldera Spas Niagara Replacement Cover
The Caldera Spas Niagara takes the AIRCAP 1™ Large — a foam-free replacement hot tub cover for square spas 89"–91". The Niagara's cabinet measures 89" x 89", inside the Large's range. The cover weighs 35–40 lb for life, costs $1,195, is engineered to comply with ASTM F1346-23, and carries a 3-year limited warranty.
| Spa cabinet | 89" x 89" |
|---|---|
| AIRCAP 1™ size | Large fits 89"–91" |
| Cover weight | 35–40 lb — constant for life |
| Price | $1,195, free US shipping |
| Skirt | Ziptech™ modular, three lengths included |
| Safety | Engineered to comply with ASTM F1346-23 |
| Warranty | 3-year limited warranty |
Why the Large fits the Niagara
The AIRCAP 1™ comes in six sizes covering square spas from 77" to 94". Each size is built to overhang its band slightly — that is how a spa cover is meant to sit — so the Large, which fits cabinets 89"–91", covers the Niagara's 89" x 89" shell with the right overhang. Instead of a rigid foam core wrapped in vinyl, the AIRCAP 1™ uses welded drop-stitch construction (the material of premium inflatable paddleboards): a sealed air chamber that cannot absorb water, so it never becomes the waterlogged, two-person lift that ends most foam covers.
Cabinet dimensions can change between model years. Before ordering, measure your Niagara side to side across the top of the cabinet in both directions — the SureFit™ guide walks through it in two measurements. If your spa measures between two sizes, round up.
Other Caldera Spas models we fit
Not a Niagara?
The Spa Fitter matches 363 models across 25 brands to the right AIRCAP 1™ — or measure any square spa with SureFit™.