The 2024 Bosphorus Cross-Continental Swim - by Serpentine Swimmer Luke Belfield

The Bosphorus Race is a 6.5km swim from Asia To Europe; the taglines include: “2 Continents, 1 Race”! And “The Cross-Continental Race”.  The best way I would describe it however is a "unique, rapid, technical, navigation race".  I’ll expose the cheat-codes to make you fly.

There are a myriad of reasons that make this race like nothing I’ve swam before.

• The romantic idea of beginning on the shores of one continent and, relying solely on your athleticism, a swimsuit, goggles, and a swim cap, reaching another continent… ticketless… without the need for a ship, plane, or train. Who needs a bridge? Breathe to the left with Asia in your periphery vision, stroke, stroke, stroke, breathe to the right with Europe in your periphery vision. You get the idea!
• It’s a closed race; the race closes one of the busiest shipping lanes in the world
• You experience what it's like to fly. The Bosphorus swim is a fun way to impress your swimming friends who know the stats, as it's incredibly fast! I completed it at a pace of 1:00min/100m (my usual 6.5km pace is closer to 2:10min/100m). To your non-swimmer friends, you're moving at an Olympic speed while crossing continents at the same time.
• It is repeatedly on the top 100 best open-water swims list; it is an old, historic, bucket-list race. It has taken place every year since 1989, yes including 2020 and 2021 covid years. 2,800 people enter from nearly 80 countries.
• It is broadcasted live on Turkish national TV, the BBC1 equivalent. At the start line, there are Turkish politicians in VIP boats, Olympians and Turkish Olympic committee, and the cameras and press are insane; helicopters, ships, drones… the full works!
• Join the many famous Olympians and star guests alumni
• Turkey; the exchange rate is kind on the wallet (at time of writing in 2024, despite race cost being very expensive, hotels and flights were cheap). It is simple to fly to. Food is great.
• Difficulty: the easiest 6.5km you’ll ever do. It is a navigation race! If you use feel, sight, spacial awareness, and follow the instructions, you’ll fly!

There are two ways for British swimmers to enter; via SwimTrek or individually via bogzali website. I entered individually via the Bogzali website. I have done many events individually (including multiple Ironmans and ChillSwim events) and relish all ways of entry (with a travel company like SwimTrek, with supporters or in a group with other racers, or completely individually). There are trade-offs to those three and some events are better than others for travel companies or entering individually. If I were to re-enter this particular event, I’d likely enter it with SwimTrek. Despite making two very good friends that I still keep in contact with, socialising was a bit more of a challenge compared to other races. I will detail the best training spots for people who enter it individually.

Applications open 1st January. Despite being told it was oversubscribed, I got in 1st time. I don’t know if it was luck, but I’ve heard past Brits have a similar experience. There is a quota of 300 swimmers per nation. If your nation exceeds that value, then you need to qualify. Therefore, in Turkey (where they have 1,400 quota, not 300), Russia, or Kazakhstan, it is competitive. For UK, it was not (in the year I applied)!

You need to get a medical (a GP letter suffices) and your swim coach needs to sign off that you’re a competent swimmer with a copy of their certificate. If you miss the cut-off date for submitting these docs (late March/early April), you are likely not to get your race entry refunded. Therefore, before applying, please have a swim-coach sourced with the pertinent certificates and who is happy to sign off. It also states there is a 2hr cut-off time, which made me incredibly nervous. I’m not a super strong swimmer and my time for a 6.5km sits around 2hrs20mins at best. I did this swim in 1hr4mins. Do not worry about the cut-off if you have a competent front-crawl.

I have no evidence as to why these rules are implemented, but here are some rules that took me by surprise:

• No Watches – This really annoyed me. As a data-nerd, reflection-nerd, Strava enthusiast, and to capture my maps, I love my Garmin. Stated in the handbooks for safety reasons, which makes absolutely no sense! My theory, based on no evidence, is because there will be patterns on the fastest routes, which could give data nerds an unfair advantage?
• Cut-Off Time – 2hrs (likely to get businesses back. If you are a half competent swimmer, please don’t worry, I unnecessarily did!)
• No Tow Float – C’mon guys? Whirlpools and reverse-currents. Why not add an extra layer of safety?
• (not conclusive) No Wetsuit – I didn’t see anyone in a wetsuit. I’m a skins swimmer personally. You aren’t allowed any neoprene, so why would anyone want one, I don’t know?

If you understand the geography, you will understand the currents. If you can understand the currents, you’ll fly; this is vital in understanding my “cheat-codes”!

Turkey has two Straits: Bosphorus Strait and Dardanelles Strait. (I’ll speak more about Dardanelles Strait and its history at the end because it is fascinating). Both Straits connect Asia and Europe. Both Straits have turbulent currents due to two seas meeting. Both Straits are natural.

The Bosphorus specifically is a technical, navigation race because the geography means you have both strong currents and strong reverse-currents.

The Bosphorus has two streams with two very different types of water entering the Bosphorus from multiple seas:

• The upper stream is the lighter sea, less saline, from the North East, because the Black sea holds less salty water. The salinity of the Black Sea's surface waters averages between 17 and 18 parts per thousand, which is approximately half that of the oceans. The Black Sea is also further North and has a colder temperature.
• The lower stream, is the heavier sea, more saline, from the South West, because The Sea of Marmara holds more salty water. The saline water comes into Sea of Marmara via the Aegean and the Mediterranean Sea. Naturally, the Mediterranean Sea is further South but also has many Southern Seas connected to it, hence it is much warmer.

If you're flowing with the current, then it's great, but if you slip into the reverse current, which is very easy to do, then you will be fighting it; a battle you’re guaranteed to lose, which leads to many game-overs. This can happen in mere seconds if you drift into it. There are no-go zones that you will be fished out of by kayakers and boats if you get caught in these reverse currents. It's also very easy to misjudge the finish line and be swept with the current to the aptly known "collection line". I’m told there are whirlpools.

So why all this talk about less saline, colder water? Well, that is one way you gauge which current you're in via the temperature and saltiness. The temperature can vary (according to locals) by about 7°C. It is mad when you drift from one current into another! You can tell!

There are four reverse-currents, the tough one to avoid at all costs is called Şeytan akıntısı, which translates to "The Devil's Current" named by the Turks. I went in on Friday (… and Saturday… and Monday) with other swimmers to test just how strong it is! It was great, but more about training spots later…

• Anadoluhisari (Asian side)
• Kucucksu (Asian side)
• Bebek (European side) – The Devil’s Current (Şeytan akıntısı).
• Arnavutkoy (European side) – just before Galatasaray Island, which is why it’s an important landmark

If you stay in the currents, the rewards are massive. Many PBs have been made over 6.5km, including mine. The Bosphorus record was 39:14 in 2013, which is outrageous!

I’ve swam Ullswater, so when people describe cold water in this Bosphorus race, we’re talking 17°C-20°C. And warm was 23°C- 27°C. So it’s basically all a bath!

An absolute must do is the Bosphorus Race Course Boat Tour. The race organisers offer, for about $15, a review of the course. As you’ll be disqualified for using a watch (argh), it is a good opportunity to get a nice Garmin/Strava map, so pro-tip, set your watches on the return journey! I also figured out my training spot from the boat (more on that later too). But that’s not the key reason to do it… it’s because you can gauge what stream you’re in via landmarks along the Strait. The Boat Tour points out which landmarks these are at an eye level. They also give information I’ve included in this blog. It’s also a great opportunity to meet other swimmers.

• Start
• Both Milestone: Fatih Sultan Mehmet Bridge, dip in bridge signifies the middle.
• European Milestone: Rumeli Fortress. Castle
• Asian Milestone: Küçüksu Kasrı. 19th Century, Armenian architecture. Balyan.
• Asian Milestone: Küçüksu Pavilion
• Both Milestone: High Electric Voltage Line wires and tower python via big. biggest dip signifies the middle.
• European Milestone: Bebek on European side is key race. Currents, avoid!
• Asian Milestone: Television tower is Asian side. Big mosque.
• European Milestone: Galatasaray Island is phone advert; Huawei
• European Milestone: Turkish Flag.
• European Milestone: Event Village: Cemil Topzulu Parki
• Finish
• Bonus Both Milestone: Second Bridge. 15 Temmuz Şehitler Köprüsü… you dun goofed! Hopefully you’ll be saved at the collection zone with a fish net!

My strategy was a combination from many sources: from Laure's blog post, Ramazan the Bosphorus Swimmer, the official boat tour, but mainly from a local who had competed 13 times on the boat. His English wasn’t great, but my new Turkish friend living in London translated (shout-out to Mert!).

Two schools of thought.

• Once you hit the cold water, swim straight, never leave it!
• The cold water are the peripheries, get into the cold water, then keep swimming a little further into it, as the current will be strongest in the middle of the current, not on the periphery. Basically, get further inside the cold water once you hit it. Same rules apply, never drift out.

I followed more of the latter

Bilateral breathe to assess if I'm in the middle. Are the cars about the same size? Also easier to use bilateral breathing on landmarks, like the bridge to assess if I’m in the middle. Is the underbelly about the same distance either side?

Usually, I never breaststroke in a race, but I used a quick couple of breaststrokes as an invaluable tool, as this is a navigation swim. You can adjust direction much easier, can see which way the waves are rippling, and taste the saltiness a little more elegantly.

Meerkat and crocodile eyes sighting are more important than a super-efficient stroke. So, sight! Do not rely and follow other people’s bubbles (like I do on other races).

• Jump In Water, you want to be swimming 45°. If you swim 90° to the European side, the current will nudge you 45°. THE MOMENT you hit the cold, follow that current, this should be the middle, your friend, swim straight. Aim for the middle point of the bridge.
• 1st checkpoint, middle part of the Fatih bridge
• 2nd checkpoint, High electric voltage line. Middle part. Closest part to the sea.
• 3rd checkpoint; Galatasaray Island. Many theories on how to handle Arnavutkoy’s inevitable reverse current, as you must swim through it. This is the part that can make or break your race. The directions have been simple until now, and (in my opinion) this is where all the value of this blog’s lies (as well as being in one location).

Galatasaray Island is about 300-400m of the finish. The official Bosphorus Race video and advice given by the officials are in theory no. 1. The locals advice is in theory no. 2 and 3.

Stay in the middle of the current until you reach Galatasaray Island. Once past the edge of Galatasaray Island, swim to the finish. This takes you out of the speedy current and into the end of Arnavutkoy’s reverse current.

Theory No. 1 will work for well for many swimmers; however, I was told by many locals the better option for the majority of swimmers is to stay with the current until you are 100m-150m past Galatasaray Island and then cut in directly to the finish. This means you are with the current for longer, and against the current for shorter, despite being a slightly longer route (basic trigonometry).

Theory No. 2 will work for well for many swimmers; however, I was told by many locals the better option for very confident strong swimmers who relish reverse-currents. Stay with the current until you are 250m past Galatasaray Island (which basically guarantees that you cut out the end of the Arnavutkoy current) and then cut in directly to the finish. The handy thing about this tactic is that you can stay head down, not gauging metres, because there is a big landmark about 250m past Galatasaray Island; the Turkish flagpole. So when the flagpole is 90° to your shoulder, then cut in. This means you don’t need to stop, sight, or judge, you can just push in the current, see the flag with a normal front-crawl stroke, and then push hard, very hard and empty the tank! This will result in a more J-like shape than a straight 90° turn because of the currents, so it’s a trade-off; sacrifice distance for being in the right currents longer. The issue with this high-risk, high-reward tactic is that if you aren’t strong enough, you may be swept by the current that’s helping you and end up in the fishing nets, which results in a DNF.

It went incredibly! I managed to complete it in 01:04:34. I think my closest 6km PB sits around 1:55:XX, so it really shows how strong the currents get. 

Pippa Middleton got a 01:05:48 back in 2014, incomparable as a different race, but still a cool thing to say :D (eat my bubbles Pippa!)

I met many wonderful people on the journey, including the famous "Bosphorus Swimmer" who I trained with on Friday, Saturday, and Monday. He has vids with 3million views on Insta for his swimming videos :D He basically took me under his wing. Spoke with a European Bronze Champion who was 65, she won her age group and later, I messaged her; she smashed me in 00:58:XX. Then I met this Oncology Dr who works at next to my flat and lives in South London. We are still very much in touch and planning to organise a race together.

The race itself was rapid. I followed Galatasaray Island theory no. 3 that the locals gave, not what the race handbook and organisers recommend. Basically, sticking to the colder, less salty, Black Sea water to catch the currents. Sighting with landmarks by staying in the middle. The tough bit was always going to be the reverse currents at the end. I cut in 300m after Galatasaray Island and swimming 90° to the finish line. Most people took the easier, less quick option of swimming longer in the current at 45°, but they are guaranteed to finish. My swim was risky, and I had confidence in my pace (or was it Dunning-Kruger). I overshot it by about 25-30m unfortunately, so if I had done it more accurately, could have shaved off some time.

I also was swimming my longest swim, Windermere six days later. I was conscious of my shoulders at Galatasaray Island. Now I know these tips, I’d love to do it again, but probably best for me to focus on The English Channel and Jersey to France in 2025 instead.

I executed this plan just as hoped. Still unsure if I left it a little too late, as I did have to swim a bit back then forward, but I ended up in the middle of the barrage, not at the end! There was lots of traffic at the first two ladders, none at the end. I got in a middle ladder almost immediately, so that shaved off some vital seconds too.

I’ll be honest, Monday was my favourite swim with Mert and Bosphorus Swimmer!

The race was on Sunday. When I was on the Official Boat Tour on the Friday, I noticed there were about 10 swimmers in the Bosphorus. These swimmers were moving nowhere. I immediately pinned my location on my Google Maps and after the boat tour equipped with my trunks, goggles, watch, and cap, made my way down there. There were about 60 swimmers, mainly Russians and Kazakhstanis. And the guide; The infamous “Bosphorus Swimmer”! He told me this is the Devil’s Current and where he trains daily. This location is between Bebek and Arnavutkoy (map below). This free-spirited man’s office was this wonderful body of water. He spotted out to me dolphins flanking cargo ships. He took me under the road on a cave like dive. But most of all, he showed me the ropes of how to get some training in and gauge how strong these currents are! Give him a follow on Insta:

https://www.instagram.com/bosphorusswimmer?utm_source=ig_web_button_share_sheet&igsh=ZDNlZDc0MzIxNw==

There are two ladders (also on map below). Walk against the current 200-300m. You look left, look right, any ships? Yes! Wait until coast is clear. Jump in. Swim as hard as you possibly can, you will either be swimming backwards or breaking even. Then you get tired and the inevitable happens, you get swept to the first ladder. If you miss this, you can get the second ladder… I never missed the second ladder! Don’t advise you to roll the dice on missing this second ladder! The other option is to swim with the Devil’s Current. I’m talking 00:50min/100m for 200m. You fly!!

I was drained by Friday evening. It was so much fun, I came back on Saturday… and Monday! It genuinely was the best part of my holiday, dare I say, better than the race! I took my Serpentine Turkish/London Dr friend on the Monday too. It was lush! Give Bosphorus Swimmer a follow on Insta, you won’t be disappointed with his content!

For such a busy shipping lane, the water was surprisingly super clean! Visibility was very clear, you could see very far in front. The taste of the water was refreshing, especially the less saline water. The fact it is teaming with wildlife implies a healthy ecosystem. Whatever Istanbul is doing, they’re doing it right!

I saw about 40 Moon Jellyfish and did not get stung. Thankfully no Barrel Jellyfish, or Comb Jellyfish on the race whose sting is a bit more painful. The sights were incredible too. My three favourite landmarks were Çamlıca Mosque (which took the biscuit), Rumeli Fortress, Kuleli Military High School. Küçüksu Pavilion was much smaller than I thought it would be. The cars and houses were tiny.

On my other swims with The infamous Bosphorus Swimmer, I saw about 10 Comb Jellyfish (as much as I hate Jellies, no denying how beautiful they are). Crabs. About 300-400 fish (unidentified). But most cool, Dolphins who were flanking the ferries and cargo ships (yes in the Bosphorus).

Record - 39:14.   2013

In 2024, there were 2,833 participants. 1,400 foreign, 1,433 Turkish. From 77 countries. Quota capped at 1,400 foreign swimmers.

From: Kanlica Ferry Port, 34810 Beykoz/İstanbul, AsiaTo: Cemil Topzulu Parki, Kuruçeşme, 34345 Beşiktaş/İstanbul, EuropeEvent HQ: Cemil Topzulu Parki

- Mark Spitz, 2012

- Ian Thorpe, 2013

- Inge de Bruijn, 2014

- Pippa Middleton in 2014. 1hr 5mins (not that I’m competitive, but I beat you by 1 minute, I hope you relished the taste of my bubbles!)

- Adam Walker 2015 - Fifth person to complete the Oceans 7

- Shelled Taylor Smith 2016

- Lexis Kellt, Doug woodring

- Kirsty Coventry, Sergey Bubka 2018

- Marcos Diaz

- 2020, 2021 went ahead.

As above, there are two Straits in Turkey; Dardanelles Strait (or Hellespont) and Bosphorus Strait (or Istanbul Strait).

The Dardanelles Strait connects the Aegean Sea with the Sea of Marmara. (Note: Aegean Sea is then connected to the Mediterranean Sea in the South). It is 61km in length.

The Bosphorus (or Istanbul Strait) connects the Sea of Marmara with the Black Sea in the north. It is 32km in length; average width of 1.5 km.

Lord Byron was one of the greatest English poets, key in the Romantics movement. His greatest achievement was to prove that the Dardenelles Cross-Continental Strait is indeed possible to swim. Byron described his swim as the feat more meaningful than anything else he’d achieved, whether “political, poetical or rhetorical”. Why? Because he loved Greek Mythology, which also influenced William Shakespeare’s Romeo & Juliet! He did it to prove a point that is was doable, as he loved the Greek Mythology of Leander...

Leander and Hero; tragic romantic story, directly alluded to by William Shakespeare.

In Greek mythology, Leander (male) and Hero (female).

Hero was based in Setos, Thrace; European side. Leander lived on the opposite Asian side; Abydos, Eceabat. The Dardanelles Strait separated the two.

The Dardanelles Strait connects the Aegean Sea with the Sea of Marmara. (Note: Aegean Sea is then connected to the Mediterranean Sea in the South)

The Bosphorus (Istanbul Strait) connects the Sea of Marmara with the Black Sea in the north.

Setos and Abydos were at war.

Hero, virgin priestess of Aphrodite, swore an oath to Aphrodite that she would serve under her and hence became a nun. Hero was beautiful but bound to a tower which had an old lady living inside who fell asleep each night early. Hero was seen at a festival by Leander; they fell in love, but Hero couldn't be seen having a relationship openly with anyone due to her promise to Aphrodite. So, Leander secretly swam the Hellespont each night to visit her, guided by a light from her tower. They had a secret love affair because of virginity that Aphrodite would not approve. One stormy night the light was extinguished, and Leander drowned; possibly by Poseidon (in some versions Poseidon helped guide him with seahorses. Poseidon admired his beauty and gave him the superpower of being undrownable. In other translations, he purposefully forced him to drown). Hero, seeing his body on the shore, asked Aphrodite to bring him back to life in the name of love. If I can’t be with him in this life, I'll be with him in the afterlife, so she drowned herself in the name of love. Sound familiar Juliette?