Water-resistant & lightweight
AirLoc™ panels have no foam core to soak up water, so the cover weighs the same out of the box and years later: 35–40 lb, depending on size.
Learn about water resistanceSpa Fitter
Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) Replacement Cover
The Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) takes the AIRCAP 1™ Small — a foam-free replacement hot tub cover for square spas 83"–85". The Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)'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.
Your size: AIRCAP 1 Small
Cabinet 84" x 84" fits 83"–85"
AIRCAP 1™ is a foam-free hot tub cover: rigid AirLoc™ air panels with no foam core to waterlog, a light 35–40 lb.
$1,195 with free shipping, usually at your front door within 3–5 business days.
Wrong size? Swap it or return it within 30 days of delivery. We pay return shipping. How it works (fit guarantee)
Finishing on your computer?
3-year limited warranty · In 100+ hot tub showrooms
AIRCAP 1™Made for a lighter lift.
AIRCAP 1™ Small · Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)
Buy the SmallFit at a glance
| 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 |
Measure straight across the top of your spa, edge to edge, both ways, in inches.
Watch it open and close on a cover lifter
Why the Small fits the Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)
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 Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)'s 84" x 84" shell with the right overhang.
At 84" the Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) sits mid-band in the Small's 83"–85" range, 1" off the bottom and 1" off the top. Within Catalina Spas, the Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) shares that 84" x 84" cabinet with Samoa (Samoa Solo, Samoa Premium, Stealth Samoa) — same footprint, same cover. The 12 Catalina Spas models we fit sit on 8 footprints, and the Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) is on number 3 of 8 from the smallest; together they span 4 of the six AIRCAP 1 sizes.
Cabinet dimensions can change between model years. Before ordering, measure your Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) at its widest point across the top, in both directions, including any acrylic lip that overhangs the cabinet — the SureFit™ guide walks through it in two measurements. If a figure you have found elsewhere is larger than ours, an overhanging lip is the usual reason. 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.
How the AIRCAP 1™ is built
Instead of a rigid foam core wrapped in vinyl, the AIRCAP 1™ uses welded drop-stitch construction: a sealed air chamber with no foam to absorb water, so it does not become the waterlogged two-person lift that ends most foam covers. More on how it insulates, how it holds up, and why it is foam-free — or estimate what your current foam cover weighs.
What customers are saying
Awesome product, my kids don’t complain about the cover anymore…
Best $$ I ever spent!
What this company has created in terms of an original and revolutionary product is nothing short of amazing.
For a reasonable price, I can cover my spa with a top that won’t get musty.
Nice and lightweight
…set up was super easy and took about 15 min total.
Installation was a breeze and we love it already!
Great customer service still matters, and frankly, not enough companies deliver it anymore. This company does, and that deserves recognition.
Do not wait to buy one.
01 / 09
Thoughtfully engineered
Built to solve the
problems of foam.
Three practical reasons to rethink your next hot tub cover.
Consistent insulation
The sealed AirLoc™ air core has nothing in it to absorb water, so its insulation stays consistent for the life of the cover.
See how AIRCAP insulatesReplaceable skirt system
Three ZipTech™ skirt lengths come in the box, and a worn or damaged skirt can be replaced on its own, without replacing the whole cover.
See how ZipTech worksEvery detail matters
Purchase with confidence.
30-day returns
Fits or we make it right. Wrong size or changed your mind? Swap it or return it within 30 days of delivery. We send a prepaid return label and there’s no restocking fee. Covers must come back in like-new condition with all parts. Bought from an authorized retailer? That retailer’s return policy applies.
How the fit guarantee works3-year limited warranty
Backed by a three-year limited warranty against manufacturing defects.
Warranty detailsFit assistance
Use Spa Fitter™ or SureFit™, or contact us before you order and we will confirm your size.
Get fit helpCatalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) cover: common questions
Need help? Contact thrml. to confirm your fit before you order.
What size hot tub cover fits the Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)?
The Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) takes the AIRCAP 1 Small, which fits square hot tubs measuring 83"–85" across. The Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)'s cabinet measures 84" x 84", inside that band. Measure your spa side to side across the top of the cabinet to confirm before ordering.
Will the AIRCAP 1 fit a Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)?
Yes — the Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)'s 84" x 84" square cabinet falls in the AIRCAP 1 Small's 83"–85" range, and the ZipTech modular skirt system ships with three skirt lengths so the drop over the cabinet adjusts without a custom order. Cabinet sizes can change between model years, so confirm with two quick measurements.
How much does a replacement cover for the Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) cost?
The AIRCAP 1 costs $1,195 in every size, including the pump, three ZipTech skirt lengths, and tie-down straps, with free US shipping and 30-day returns. Unlike a foam cover it has no foam core to waterlog, so it stays at its original 35–40 lb weight for life.
How heavy is a replacement cover for the Catalina Spas Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)?
The AIRCAP 1 Small weighs 35–40 lb and keeps that weight permanently — its sealed drop-stitch air core cannot absorb water. A foam cover starts at 40–75 lb and gains weight as the foam saturates.
| Model | Cabinet | AIRCAP 1™ |
|---|---|---|
| AIRCAP 1™ X-Small · fits 80"–82" | ||
| Armstrong | 80" x 80" | X-Small |
| AIRCAP 1™ Small · fits 83"–85" | ||
| Carlton | 83.5" x 83.5" | Small |
| Hampton | 84" x 83.5" | Small |
| Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) (this page) | 84" x 84" | Small |
| Samoa (Samoa Solo, Samoa Premium, Stealth Samoa) | 84" x 84" | Small same cover as the Neptune (Neptune Solo, Neptune Premium, Stealth Neptune) |
| AIRCAP 1™ Medium · fits 86"–88" | ||
| XL 21000 | 87" x 87" | Medium |
| AIRCAP 1™ X-Large · fits 92"–94" | ||
| Berkshire | 92.5" x 92.5" | X-Large |
| Nantucket | 93.5" x 93.5" | X-Large |
| Raptor (Raptor Premium, Stealth Raptor) | 93" x 93" | X-Large |
| Saber (Saber Premium, Stealth Saber) | 93" x 93" | X-Large |
| XL 22000 | 92" x 92" | X-Large |
| XL 26000 | 93" x 93" | X-Large |
Your cover. Your way.
Not the Neptune (Neptune Solo, Neptune Premium, Stealth Neptune)?
Every Catalina Spas model we fit is on one page, each with its cabinet size and cover — or open the Spa Fitter for another brand, or measure any square spa with SureFit™.
Prefer to shop locally? Find one of 100+ showrooms.
Available in over 120 authorized hot tub showrooms across 34 states.