Kit review: OSS swimmers put sustainable costumes through their paces

Inka Creswell in Baktoka/ Rob Hyland

When it comes to swimming sustainably – first and foremost the most sustainable item is the swimming costume you already own. But if you are considering buying or gifting someone with a swimming costume, this kit review showcases some of the few brands that go above and beyond with their commitment to producing sustainable swimwear in an ethical and sustainable manner.

Deya Ward in Finisterre/ Stuart Swift
Aisha in Ruby Moon/ Stuart Swift
Kari in Deakin & Blue/ Lou Barber
Inka Cresswell in Baktoka/ Rob Hyland
Kari in Deakin & Blue/ Lou Barber
Aishah in Ruby Moon/ Stuart Swift

Baktoko – Inka

“I thought the swimming costume was really well made, I absolutely love the print! It’s bold enough that it really stands out in photos. The design of the costume is great for more active swimming so brilliant if you plan on constantly jumping in and out of the water, are going to be free diving in strong current or for more active water sports like surfing or kayaking. 

I felt really secure in it – no concerns that anything was going to accidentally pop out.. which is great for me scuba diving because I’m often lifting tanks etc so you want something that isn’t going to slip off your shoulders when you’re leaning over to pick up heavy items. Nothing worse than a falling down swimming costume when your hands are filled with tanks and camera gear, its a situation I have found myself in far too often! I also really like that there’s no ties. When I’m wearing a costume under wetsuits the pressure of the wetsuit against neck or bikini bottom ties can be really uncomfortable and leave little bruises especially if they sit at my hips or waist where my weight belt sits. This design was really comfortable and not restrictive, however if you are on the bustier side you may find this costume doesn’t offer enough support. It’s also fairly on the conservative side which is great for if you’re working and don’t want to be too exposed but the lower back detail and print still makes it feel young which is great.

Inka in Bakota/ Rob Hyland

One of my favourite details was actually the label which makes a point of saying  that the product is made up of plastic that would have ended up in landfill and mentions their ethical working practices which is something really important to me.”

COSTUME KUDOS: Batoko is a micro-business and aims to stay that way. By consciously keeping their swimwear collection small, the brand ensures it works at a sustainable pace that’s kinder to the planet and the people that make them. It also means items are never over-produced.

Inka is wearing the Batoko Shark Swimsuit (£50). 

Deakin and Blue – Kari

“We need more fun swimsuits in our lives – I have tried the new reversible black Zoo print costume by Deakin and Blue. The fabric is a beautiful Liberty Print, featuring a selection of animals, my favourite is a pink anteater, which unbelievably is not silly or infantile. I am feeling a bit self conscious about the lockdown weight I have accumulated, but Deakin and Blue, you have made a costume that has exactly the right amount of support, and because it has a double layer of material, I did not feel exposed and naked.

Kari in Deakin & Blue/ Lou Barber

The cut and fit is amazing, I  love the way the costume felt snug around my bottom, it is a sporty costume, deceptively simple, no extra bits of shim sham, but glamorous at the same time. A costume I would use for an event, swim round an island, play with my grandchildren, and even go on a cruise, if I did such things.”

COSTUME KUDOS: Deakin and Blue’s swimsuits are designed with different body shapes in mind, as well as being made from ECONYL.

Kari is wearing a Deakin and Blue Classic Reversible Swimsuit in Zoo print and Black (£130).

Ruby Moon – Aishah 

“Currently there are not many options for modest clothing that are conscious of sustainability. The head cover is detachable on this costume, and there are buttons to make sure it’s in place. I didn’t button it when I was in the water and it stayed nicely on my head (it didn’t float). The head cover also covers the neck and not just the hair (some modest swimwear only includes something similar to a swimming cap). 

Aishah in Ruby Moon/ Stuart Swift

Since it’s detachable, you can wear the swimwear without the head covering. The length of the top fits nicely; it’s not too long, but still covers my bottom. The top is loose and not form fitting, so the body’s curves/shape is not too obvious, making it more comfortable for those who dress modestly. The legging stretches really nicely. (I have quite big thighs and was initially worried when I looked at the leggings but they fit really well). The top can be tied to the legging, so that you can swim more comfortably (and the top will not float /come off).”

COSTUME KUDOS: Oeko-Tex certified – no harmful dyes/chemicals used.

Aishah’s costume from RubyMoon is in the modest collection and still in development.

Ocean Positive by Fourth Element – Lily

“I absolutely love this swimming costume. It is my go-to costume every swim. It fits like a glove and pulls everything in so it’s actually very functional as a swimsuit. I love doing longer swims and doing tumble turns when I’m in a pool so a swimsuit that is more focused on the  athletic rather than aesthetic is always my first choice, and the great thing is that this one pleases both.

I particularly love the open back as my true love is naked swimming so the backless feel means I can feel the water against my skin as I jump in. The costume is also composed of impressive recycled materials including LYCRA® XTRA LIFE™ – you can feel that it has a long-lasting fit.

COSTUME KUDOS: Ocean Positive by Fourth Element provides costumes in the lower price range whilst maintaining highest standards for sustainable and ethical sourcing. The combination of materials ensure  strong resistance against degradation from chlorinated water, the heat, and sunscreen lotions up to 10 times longer than unprotected fabrics. 

Lily is wearing the Gili swimsuit from Forth Element in blue navy. (£20). 

Davy J – Lou

“The swimming costume has solved a lot of the challenges I have when searching for swimwear. I usually need a different size in tops and bottoms which makes it difficult to find one piece with the right fit. Having separate pieces which combine to make a whole swimsuit is the perfect solution. It is also great to know I can combine them with other bikini tops or bottoms depending on the type of swim activity I’m using it for.

The quality of the swimming costume is brilliant. The material is thick and feels like it will last a lifetime. It fits snugly and doesn’t have any zips or straps so I could swim without worrying about it moving or coming undone. The only downside was I found it quite difficult to get the top on and off over my head. It was harder than usual to change when getting out of the water, but I think the overall benefits of the style outweigh any negatives. Aside from that, I know it will be super versatile and I’ll definitely be using it for swims throughout the year!”.


Lou’s is wearing the Davy J super high waisted briefs (£65) and the Body Top in black (£60). 

Davy J – Val

“I’ve never really known about the market for technical swimwear but this costume certainly ticks all the boxes.

When I first tried on the smaller size, being generally a size 14, I found myself wrestling with the tightness of the fit, rather like doing two rounds with Mike Tyson. So I initially opted for the size 16 which was roomier. Being curvaceous I can get anxious about my bum and boobs popping out in all the wrong places, but the double lining of this ergonomic costume sees to all that. Good weather and an invitation to a friend’s natural pond in the Radnorshire hills was the first outing. Hauling myself out over a slippery, weedy pond liner would have been a disaster in the past – a boob here and a boob there – but snug as a bug they were in this Little Black Swimsuit and with my Pilates core switched on I acquitted myself admirably.

The next day I was off to the River Wye but I decided to try the smaller size on again as there is definitely some give in the suits when they are wet. It fitted, it felt fabulous and I have to tell you I was feeling a somewhat sexier 60-year-old swimmer in this snugger suit. Once the suit is wet it becomes a second skin holding bum and boobs in place rather like I imagine toupee tape does with hair. I strode out along the beach, nothing was hidden from view and yet I had no body conscious concerns at all in or out of the water … Bo Derek eat your heart out!”

COSTUME KUDOS: UK based, reduced travel for delivery .

Val’s is wearing the Little Black Cossie by Davy J (£140).

Ruby Moon – Melanie

“The first thing I noticed about this swimming costume is the comfort. I am very broad on the top and so  I really enjoyed the shape of the costume and how it felt. This costume is from the ‘gym to swim’ range and I put it through its paces with some weights and boxing before heading straight for a swim. 

I felt fully supported in this costume, it works well to combine a swimming costume for training with a sports bra for exercise. I felt supported whilst also feeling not restricted at the same time. I really like the sporty look – especially the racerback top half, and the shape with the two coloured straps worked so well for swimming and exercise. A perfect item for enjoying a swim, as well as training  – both in and out of the water!” 

COSTUME KUDOS: certified 42% less carbon emissions, no underwire or metal contaminants. 

Melanie is wearing the Ruby Moon Sorphea Swimsuit (£95).

Finisterre – Annie

“This Finisterre Zenith costume is the dream! To be able to swim and be in water, whilst wearing a cossie that is directly tackling the issue of plastic pollution by reusing nylon waste, carpet offcuts and old fishing nets, feels like a real comfort to the mind of a marine biologist.

When it comes to swimming, I’m more of a dipper. Once weekly, throughout the year (yes even February), myself and a big team of thalassophiles (ocean lovers), the Morning Dippers, rise at 6am no matter what the weather, temperature or previous evening’s antics, to freshen up before the day and clear the mind. 


Annie in the Finisterre Zenith

When you’re entering the cold zone at sunrise, comfort is essential. Whilst the water is currently a balmy 17 degrees up here in Leicester, this costume made me feel incredibly confident, both in my body and mind. I’m not always the first one to toss off the outerwear and strut around in a wee two-piece, so the neck height and flattering design made me feel really wonderful. It’s a practical shape, suiting those two-minute cold dips as well as triple-dip days where you need a fast-drying cossie. (Helpful tip – do not leave on the roof of the car to dry before driving off). 

Thanks Finisterre – this swimming costume will be coming on some seriously chilly adventures.”

COSTUME KUDOS: Finisterre has a repairs workshop for main items of its range to ensure that each item continues to be worn time and time again, to encourage slow fashion.

Annie is wearing the Zenith costume in turquoise (£85)

ABOUT DEYA: Zoology, swimming and sustainability

A few years ago outdoor swimming shifted from an activity I enjoyed a few times a year, to an integral part of the week. Embracing the outdoors by swimming through it – whether that be the ocean, lakes, quarries, rivers or lidos – allows you to have a very special and unique perspective of the natural world around you. 

That awareness comes in many forms. Maybe you notice how a marine lake or other swimming spot changes form with the changing seasons. You might follow the shifting behaviour of wildlife within the body of water you are immersed in. Maybe whilst you glide down a river, you suddenly notice water vole holes under the river banks or a glimpse of ducks with their ducklings safe between the reeds.


I notice this particularly during summer with the emergence of the grannom and mayflies, followed like clockwork by the acrobatically-leaping trout in the warm-coloured hours of late May and June afternoons. These are things that usually would be hidden when passing by on foot. As a zoologist, these close encounters with wildlife as I swim with just as a bobbing head above water is one of the things I cherish most about outdoor swimming. Having such a close association to the environment you swim in also leads to you becoming acutely aware of its health as a natural space: the quality of the water, the impact of plastic pollution and the conditions the swimming areas are left in. 

As a zoologist, these close encounters with wildlife as I swim with just as a bobbing head above water is one of the things I cherish most about outdoor swimming.

The great thing is that sustainable and ethically sourced swimming costumes are becoming more common – it was hard to select just a few for this kit review! We selected the products above on the basis of a range of considerations, from whether it was made locally, in the UK (Davy J, Finisterre, Deakin and Blue, Fourth Element), to whether it was vegan-friendly Oeko-Tex certified, with no harmful dyes or chemicals (RubyMoon). But what all the brands and costumes have in common is their use of sustainable materials, with the aim of being durable and long lasting.

Deya Ward in Finisterre/ Stuart Swift
Deya Ward in Finisterre/ Stuart Swift
Deya Ward in Finisterre/ Stuart Swift
Deya Ward