Tankini, one-piece or bikini: which Ocean Blues cut for laps, the beach and water aerobics
Forty lengths of a chlorinated pool, a day on hot sand, an aqua class with the arms overhead, a water park with children, a kayak seat. Each asks something different of a swimsuit, and the three cuts answer differently. Which piece we would reach for first, and why.
The question is never really "which is prettiest". It is "what am I going to do in it", and the answer changes the cut more than the colour ever will. A suit that is right for forty lengths of a chlorinated pool is wrong for a day on hot sand. A suit that is right for the sand is wrong for an aqua class, where your arms go over your head every thirty seconds. Ocean Blues makes all three cuts, and most of them in more than one shape, so the choice is real. Here is how we would make it.
The three cuts, and what each one is for
A one-piece is one loop of fabric from shoulder to shoulder through the legs. Nothing rides up because nothing is separate, and that is the whole argument for it. The cost is that it fits by torso length, and that it comes off in one wet piece when you need the bathroom.
A tankini is a one-piece cut in two: a top that reaches the hip and a bottom that stands on its own. You get the coverage of a one-piece with the sizing of separates, and the top comes off without the bottom. The cost is a hem that can float up in the water, which the ruched and blouson tankinis are cut to manage in different ways.
A bikini is two small pieces, and every piece we make in it is sold on its own: a triangle top, a halter, a bandeau, a brief, a cut-out bottom. You size the top and the bottom separately, which is the best answer there is to a bust and a hip that land in different letters. The cost is that there is less fabric to hold on with, so the choice of top matters more in the water than out of it.
Board shorts sit outside the three, and pair with any of the tops. A pair of Ocean Blues board shorts with a tankini top is a fourth cut in its own right, and we come back to it below.
Laps: what has to stay put
Lap swimming is the hardest test a swimsuit takes. Your arms go over your head every stroke, you push off a wall every twenty-five yards, and the water pulls at every edge. The suit that survives it is the one with the fewest edges.
That means a one-piece first. The athletic boyshort one-piece is the plain answer: a built-in bra with removable pads, wide straps that stay on the shoulder through a flip turn, and a boyshort leg that does not creep. It runs S to 3XL. The long-sleeve boyleg swimsuit does the same job with sleeves, a front zip and thumbholes, and it runs to 4XL. In an outdoor pool the sleeves are the difference between a long session and a short one.
If you would rather swim in two pieces, choose the tankini with the fewest loose parts. The V-neck push-up tankini has wide straps that cross at the back and a hem that stays down; the twist-front tankini has removable straps, and for laps you leave them on. Under either, a bottom with sewn sides and full coverage, the side cut-out bottom or the ruched-side swim bottom, holds better than a tie-side.
A bikini can swim laps, but only certain ones. The racerback sports top is built for it, with a wide elastic band and a scoop neck. The push-up halter and the tie-back bandeau are not: a halter tie works loose over a session, and a bandeau needs its straps on to survive a push-off.
The beach: sand, sun and getting dry
The beach asks less of a suit in the water and more of it out of the water. You will be dry for most of the day, you will be lying on your front some of the time, and you will want to get out of the wet parts quickly.
Here the argument turns towards separates. A bikini dries in minutes, a top comes off under a shirt without the bottom, and sand rinses out of two small pieces faster than out of one big one. The string-tie triangle top and the side-tie triangle bottom are the beach pair for that reason: nothing sewn to the body, everything untied and rinsed in a minute. The Brazilian cheeky bottom and the mid-rise high-leg bottom are cut for a beach rather than a pool, and their descriptions say so.
If you want one piece on the beach, choose one that comes off the shoulders. The shirred bandeau one-piece, worn strapless with its straps in the bag, is one; the high-cut low-back one-piece, which leaves most of the back open, is the other. The tankinis with removable straps, the twist-front and the ruched bandeau, work the same way.
Sun is the other beach question, and the honest answer is that a swimsuit is not a sunscreen. Four Ocean Blues pieces are made from UPF 50+ rated fabric: the long-sleeve boyleg swimsuit, the long-sleeve moulded-cup swimsuit, the 8-inch board shorts and the 3-inch high-waisted swim shorts. The rating tells you what the fabric was tested to let through; it does not tell you anything about the skin the fabric does not cover. We have written about what the rating means and what it does not in a separate piece on UPF and care.
Water aerobics and aqua classes
An aqua class is laps turned sideways. The arms go up, the legs kick out, and you are standing in chest-deep water where the class can see your top edge and the instructor can see your hem. Coverage matters and so does a top that does not need a hand on it between moves.
The one-piece wins again, and for the same reasons as laps. But the class adds a wrinkle: you get in and out of the pool more often, and you talk to people at the side. A tankini gives you that with a top that passes for a shirt out of the water. The ruched bandeau tankini with its straps on, the shirred cut-out tankini with its adjustable straps, and the loose-fit plus-size tankini all reach the hip and stay there. The loose-fit one is cut long in the torso, so the hem does not lift with the arms.
Under a tankini top in a class, the piece to wear is a board short. The 3-inch high-waisted swim shorts and the plus-size 3-inch boyleg shorts sit above the navel and end at the top of the thigh, which is where a leg kick wants them. The 8-inch board shorts cover more of the thigh and have pockets. Nobody needs pockets in the water; everybody uses them on the walk in.
A bikini in an aqua class is a bikini with a job. The racerback sports top is the one we would pick, and the wide-strap bandeau with its straps on is the next. Under it, a high-waisted bottom rather than a brief: the high-waisted full-coverage bottom, or the plus-size high-waisted bottom, both of which sit above the navel and do not roll when you bend.
Ocean Blues Ruched Bandeau Tankini Top
Molded cups, wire-free · Sizes S to 4XL · Full coverage
$27.99
The water park, and any pool with children in it
A water park is a day of slides, wave pools and queues in the sun, and the suit that works is the one that survives the slide. Anything with a tie is a risk on a slide; anything strapless is a certainty.
The skirted swim dress with shorts is built for exactly this day. It is a scoop-neck dress with a flared skirt and shorts sewn in underneath, so the skirt can ride up a slide and there is a short under it. The athletic boyshort one-piece is the sportier version of the same idea. Both have built-in bras with removable pads and wide straps.
If you want two pieces at a water park, a tankini set with boyshorts is the pair to wear. The blouson tankini set comes with high-waisted boyshorts that are fully lined. The high-neck loose-fit tankini set has a neck that stays put when you land at the bottom of a slide. The bikini to take is the high-waisted ruched set, top and bottom sized as one, with straps rather than ties.
Paddleboards, kayaks and anything with a seat
Sitting is its own test. A kayak seat presses on the back of the suit for two hours; a paddleboard has you kneeling, standing and falling in, sometimes in that order. You want a seat that is covered, a top that stays on when you go over, and fabric that does not hold a puddle when you climb back on.
Board shorts first. The 8-inch pocket board shorts have a lined brief inside, a high waist, and crossed straps at the leg openings that keep the hem from riding up on a board. The 7-inch lined swim shorts do the same with a shorter leg. Over them, a rash guard. The long-sleeve zip surf rash guard is cut for exactly this, with a front zip that opens over wet skin and thumbholes that keep the sleeve down when you paddle.
If a rash guard is too warm, a tankini top over the shorts is the next answer. After that comes the racerback sports bikini top, the only bikini top we make that we would wear to fall off a board in.
The table
| What you are doing | Cut we would start with | The Ocean Blues piece | Why |
|---|---|---|---|
| Laps, indoor pool | One-piece | Athletic boyshort one-piece | Fewest edges, wide straps, boyshort leg |
| Laps, outdoor pool | One-piece with sleeves | Long-sleeve boyleg athletic swimsuit | Zip front, thumbholes, UPF 50+ rated fabric |
| Beach, lying out | Bikini | String-tie triangle top and side-tie bottom | Dries fast, comes off in pieces, rinses clean |
| Beach, swimming | One-piece off the shoulder | Shirred bandeau one-piece, straps on to swim | Sewn cups, straps in the bag for the towel |
| Aqua class | Tankini and board shorts | Ruched bandeau tankini over 3-inch swim shorts | Hem at the hip, shorts above the navel |
| Water park | Swim dress or set | Skirted swim dress with shorts | Shorts under the skirt, wide straps |
| Kayak or paddleboard | Board shorts and rash guard | 8-inch pocket board shorts under the zip surf rash guard | Lined brief, straps at the leg, zip and thumbholes |
| Resort pool, mostly sitting | Bikini with structure | Push-up halter or U-wire cut-out top | Moulded cups, a tie or a buckle to set the band |
The table is a starting point, not a verdict. Every row has a neighbour on the same shelf that does the same job with a different neckline, and the shelf pages list them side by side with their size runs.
Mixing the cuts
The reason to buy separates is that the cuts mix. A tankini top over board shorts is a swimsuit with pockets. A bikini top under a rash guard is a rash guard you can unzip at lunch. A one-piece under board shorts is a one-piece you can wear to the car.
The pairings that work best are the ones where the two pieces meet. A tankini hem at the hip over a high-waisted short, so there is no gap. A bandeau top with its straps on under a rash guard, so nothing pokes through the zip. A bikini bottom with sewn sides under a swim skirt, so the skirt has something to sit on. The pairings that work worst are a low-rise brief under a tankini, which leaves a band of skin the tankini was bought to cover, and a strapless top under anything with a zip.
Where to start
Start with the activity that you do most, not the one you do on holiday. If that is laps, buy the athletic one-piece first and a tankini second. If it is the beach, buy the triangle top and a tie-side bottom, then add a one-piece that comes off the shoulders. If it is an aqua class, buy a tankini top and a pair of 3-inch shorts, and add a second top before you add a second short. If it is a water park with children, buy the swim dress and stop there.
Then buy the second piece in the same size run as the first. The runs are cut differently, and a top from one over a bottom from the other will sit at two different places on the same body. The size guide covers that in full, and it is the piece to read before this one if the letter is still an open question.
More of this sort of thing is in Swim Notes, and the Ocean Blues team keeps the whole range one click away on the front page.