Spa Fitter
Tropic Seas Spas Kona 751B Replacement Cover
The Tropic Seas Spas Kona 751B takes the AIRCAP 1™ Small — a foam-free replacement hot tub cover for square spas 83"–85". The Kona 751B's cabinet measures 84" x 84", inside the Small'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 | 84" x 84" |
|---|---|
| AIRCAP 1™ size | Small fits 83"–85" |
| 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 Small fits the Kona 751B
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 Small, which fits cabinets 83"–85", covers the Kona 751B's 84" x 84" 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 Kona 751B 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.
Every spa in our catalogue that measures 84" x 84" is on one page: hot tubs that take an 84" × 84" cover — the same AIRCAP 1™ Small, at the same price.
Other Tropic Seas Spas models we fit
Not a Kona 751B?
The Spa Fitter matches 496 models across 40 brands to the right AIRCAP 1™ — or measure any square spa with SureFit™.