Sea Level

Sea Level is an Australian swimwear and resort wear brand that sells swimsuits by cup size, from A-B up to G, with underwire options built into its bikini tops and one-pieces. The brand is designed in Australia, dates its current approach to 2018, and is sold in its home market and in the United States through a dedicated US site.

Sea Level swimwear and the bra-sized fit

Most swimwear is sold in dress sizes, which works for a bikini bottom and badly for a top. A size 12 swimsuit assumes one bust size for every body that wears a size 12. Sea Level's whole range is organized around rejecting that assumption.

Its tops and swimsuits are grouped by cup. The current navigation lists A-B, C-D, D, DD, E, F and G cups, plus a Multifit range that covers A to DD with adjustable fit. That is broader than many readers might expect from a resort brand, and it puts Sea Level in competition with the bra makers who moved into swim, such as Panache and Freya, rather than with fashion swim labels.

Wires, slings and shaping

The support comes from lingerie engineering. Many Sea Level tops use underwire cups, the same construction a fitted bra uses, hidden inside the swim fabric. Others rely on molded cups, wide underbands and adjustable straps. For a fuller bust, a wired swim top does the job a sports bra does on land: it stops movement and spreads weight across the band instead of the neck.

This is the point where a swim brand behaves like a lingerie house. Patterns need grading by cup as well as by band, and every new top multiplies the number of sizes a retailer has to stock. Brands that do it accept higher inventory costs in exchange for a loyal fuller-bust customer.

Recycled nylon and the 2018 turn

The brand's About page uses 2018 as its reference point, saying that since then Sea Level has approached swimwear and resort wear through sustainability, quality and modern femininity. The page does not give an original founding year, and no company history was found that settles it.

The sustainability claim rests on fabric. Much of the range is cut from Econyl, a regenerated nylon yarn made by the Italian company Aquafil, and the brand describes its material as regenerated nylon from pre-consumer waste. Recycled lines are grouped under names such as Eco Essentials and Sustainable Swim.

Sea Level also runs a giving scheme with i=Change, donating one dollar from every online purchase to a charity the customer picks at checkout.

What the range covers

The collection reaches well past the swimsuit:

• one-pieces, bikinis and tankinis in cup sizes
• rash guards for sun protection
• resort dresses, tops, pants, shorts and cover-ups
• sarongs, ponchos, beach bags and hats

The design language is restrained by Australian standards. The brand talks about clean lines, soft textures and relaxed sophistication, and it avoids the very high-cut, low-coverage looks that dominate the youth swim market.

Prices and selling terms

On the US site in late 2026, swimwear ran from about 73 dollars to more than 170 dollars. Shipping was free over 200 dollars, and customers had a 30-day at-home try-on period, a policy that suits bra-sized swim, where fit is hard to judge from a photograph.

Ownership and home base

The company does not name its founders or owners on its public pages, and no Wikipedia article or trade profile was found. Earlier records, including this museum's own, placed the brand on the Gold Coast in Queensland and limited its fit range to B to DD cups. Neither point is confirmed by the brand's current site, which says only that it is proudly designed in Australia, and which sells cups from A-B up to G.

What is clear from the catalog is the niche Sea Level has chosen. It sells swimwear to women who wear a fitted bra every day and expect the same support on the beach, and it lists its range by the letter on the bra tag rather than the number on the dress.

Last updated October 6, 2026