Ridzwan Rahim - Redang Channel

Pulau Pinang to Mainland

25 km (15.5 miles)

20 hours, 42 minutes on 24-25 June 2023

Observed and documented by Shamsul Hamimi Ab Rahman and Tsuyoshi Amzar Sawada




  • Name: Ridzwan Rahim
  • Gender: male
  • Age on swim date: 46
  • Nationality: Malaysia
  • Resides: Kajang, Selangor, Malaysia

Support Personnel


Shamsul Hamimi Ab Rahman

Observer on Redang Channel solo attempt in 2022.

  • World Triathlon technical officer since 2017
  • Asia Open Water Championship 2017 technical officer
  • Standup paddleboard instructor
  • Langkawi Swim Fest 2021 judge
  • Races participated: Ironman 70.3 2019; Langkawi Swim Fest 2019 (4km); Oceanman Langkawi 2018 (10km); Perhentian Challenge 2018 (16km) mixed relay runners-up; Port Dickson International Triathlon 2013-2019

Tsuyoshi Amzar Sawada

Observer on Redang Channel solo attempt in 2022.

  • Swim, triathlon and standup paddleboard instructor
  • Japan National Lifesaving Championship 1994 champion
  • Australian Bronze Medallion 1994 certification holder
  • Represented Japan at Outrigger Canoe World Championship in Hawaii, 1999 & 2002
  • Japan Red Cross water safety instructor, 1999-2010
  • Japan Lifesaving Association assistant instructor, 1995-2010
  • Races participated: Kanaka Ikalka Okinawa 30km SUP race 2014 & 2015; Labuan Sea Challenge SUP race overall champion 2014 & 2015; Labuan Sea Challenge 50km Island Canoe runner-up; Port Dickson International Triathlon age-group champion 2015, 2018, 2019; Kapas Marang International Swimathon 6.5km swim runner-up 2017 & 2018; Balok Beach Wind Challenge SUP race overall champion 2016 & 2018

Escort Vessels

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: Textile swimsuit (Speedo jammer), Speedo silicone cap, Speedo goggles, Guardian LED light during night.

Route Definition

Pulau Pinang (Redang Marine Park Centre) to the stretch of beach on the mainland between Penarik and Merang.

  • Body of Water: South China Sea
  • Route Type: one-way channel swim
  • Start Location: Redang Island Marine Park Centre (5.746189, 103.000150)
  • Finish Location: Bari Beach (5.557020, 102.879947)
  • Minimum Route Distance: 25 km (15.5 miles) (map)


The first ever attempt to swim this route was also by our team in 2022. We ended our swim after about 15 hours with an estimated 6km more to go.

MSF-ratified swim of nearby Perhentian Channel by same swimmer in March 2021. See documentation.

Swim Data

  • Start: 24 June 2023, 21:15:00 (Asia/Kuala_Lumpur, UTC8).
  • Finish: 25 June 2023, 17:57:26
  • Elapsed: 20 hours, 42 minutes, 26 seconds.

Summary of Conditions

Feature Min Max
Water Temp (C) 29.2 32.2
Air Temp (C) 30.5 36
Wind (knots) 1.5 9.7

GPS Track

Trackpoint frequency: 15 minutes. Download raw data (CSV).

Click to expand map.

Speed Plot

Nutrition: The plan was to feed every 45 minutes. The feed would be delivered to the swimmer by way of a cycling bottle placed inside a throw bag. The type of feed to be given would depend on the swimmer’s request. This time, we also incorporated a plan to keep the problem of salt mouth at bay, using mouth wash and canned peaches. These were given to the swimmer a few times during the swim. During the noon portion of the swim when the sun was at its hottest, the feeder also gave the swimmer iced water, not for drinking but for spraying on the swimmer’s head to cool down.

Observer Log

Download PDF

Swimmer Statement

By Ridzwan Rahim

LAST year (2022), my team and I attempted to swim 25km from Redang Island to Peninsular Malaysia. It was something nobody had ever done before. We did not succeed.

This year (2023), we tried again. We called our project Redang Channel Solo Swim 2023. This time, we gave it our all and succeeded.

We began from the Redang Island Marine Park Centre at 9.15pm on Saturday, June 24, 2023 and landed on Bari Beach in the mainland the next day at 5.57pm. Time taken: 20hr 42min 26sec.

For someone of my experience, I consider this a hard swim. Last year, my body cramped several times. I was stung by jellyfish twice. I did not have enough mental fortitude and ended my attempt after 15 hours with an estimated 6km more to go.

Remarkably, this year, I did not experience any cramping at all. As for jellyfish, I was stung once but it was minor and required no medical attention.

Having said that, I would say this year’s swim was even harder by comparison. Throughout the more than 20 hours, the sea was calm only on three occassions: the first hour, the sunrise and the last hour. During feeding breaks, I had to tread higher in the water to prevent seawater from coming into my mouth and my feed. I had little respite.

And yet despite the harsh conditions, we completed the swim. The followings are what we changed from last year.


After the failure of last year, we accepted that this swim would be hard. The sea would not be friendly.

I credit Abdul Razak Abdul Aziz, our team leader last year, for making me believe I could handle the swells of the Redang Channel. So this year, even though the waves were just as formidable, I did not complain and just got down to work.

We also changed our expectations for how long the swim would take. Last year, we thought we could reach shore after swimming no more than 30km. We were so wrong. This year, we revised our expections to between 35 to 40km and true enough, we clocked 37.36km.


I was a bit more relaxed this year. Instead of swimming hard, I kept my heart rate low and minimised energy use, even if it meant swimming at a slower pace.

Away from the pool, I worked on improving my posture. When doing normal daily activities such as driving, working at the computer or eating, I kept my shoulders down and my back straight.

My swim training began in Ramadan, where I would swim at 4am a few times a week to maintain swim fitness.

As soon as Ramadan was over, the long weekend swims began in earnest.

As with all previous swim projects, my coach Shauqie Aziz prepared the training plan. At its peak, Shauqie got me to do almost 18km in a single day.

This year’s training plan was different. Instead of just freestyle swimming, we also incorporated individual medley (IM) routines.

I had been learning the four IM strokes from Coach Angelia Ong since late last year. Angelia is a former national swimmer and sister of Malaysian swim star Jeffrey Ong. For my training, Shauqie varied the plan with butterfly, backstroke and breaststroke swims.

A week before I left for my swim, another coach Imran Luqman arranged for me a physio session that included dry needling. It was my first experience with the procedure.

It seems this combination of training, physio and being mindful of my energy use allowed me to swim almost 40km in the Redang Channel without cramping.


There was nothing remarkable about my diet. I live with my parents and ate whatever our helper or my sister cooked at home.

Being a small eater, I did not eat as much as most people would when training for a marathon swim.

As for sleep, Shauqie recommended a minimum of eight hours every night, but I could only get by on four hours of sleep due to taking care of my bedridden father.

Then again, I figured for the kind of swim that I do, I am supposed to be able to function for very long hours on very little food and sleep.


One of the big problems from last year was salt mouth, which caused me to lose my sense of taste and made a drudgery of my feeding breaks.

This year, my team and I devised a plan to tackle the problem: by gargling with mouthwash and eating canned peaches, as recommended by some members of the MSF forum.

There was no way to test this solution beforehand as I needed to be submerged in seawater long enough for the problem to manifest. But evidently, the recommendation from the MSF forum worked, as during the swim, I could still enjoy my feedings.

My only complaint was when my feeder made the mistake of using my feeding bottles to deliver the mouthwash. I could taste traces of the mouthwash in my feeds, even after the bottle had been thoroughly rinsed. This is something for us to improve next time.

The full effect of salt mouth did not manifest until after the swim. I could not eat or speak properly for 12 hours. Even drinking water was painful. But by then, I was already a happy man.


Unlike last year, this time we did not set any particular landing point.

On swim day, we set out by aiming for the Penarik Mosque, but really the plan was to allow ourselves to land anywhere along the stretch of beach from Penarik to Merang.

We changed course as and when the team felt necessary, based on the changing conditions of the sea.

There was a point during this mission when it threatened to fail a second time. It came at around 8km to 10km from the mainland.

The sun was at its hottest. The current was working against me. Every time I stopped to feed, the current pushed me away from the mainland.

I had been battling the choppy sea and winds all night and all morning, and did not know how long I could sustain this herculean effort. I felt I deserved a break.

I did not share my doubts with the team but they probably sensed it.

But I could not find a valid reason for ending the swim. I felt my body, breathing and heart rate were functioning normally, so I could not tell my team I was exhausted.

In that critical moment, I decided I was not going to let my team down a second time after the failure of last year. When I finally told them I was going to press ahead even if it meant reaching shore at night, they cheered. That gave me strength.

I also wanted to succeed this time for our new collaborators.

In the weeks leading up to the big swim, I had begun talking to Project Life Aquatic, a project near Kuala Lumpur that seeks to help people overcome fear for deep water. Discovering the project delighted me to no end because I had been fighting for a similar cause. It felt like meeting a kindred spirit.

I had also reached out to the Universiti Malaysia Terengganu Institue of Oceanography and Environment (INOS UMT) to obtain marine data and advice for this Redang Channel project and beyond.

So I wanted to come back from this swim and meet with our partners with a success story. This has been such a sweet achievement.


The Redang Channel Solo Swim 2023 is part of an ambitious project by our team to pioneer a series of marathon swims in the state of Terengganu that we call Terengganu Four Swims.

The series comprises swims from Perhentian Channel (17km), Redang Channel (25km), Perhentian Island to Lang Tengah Island (19km), and Redang Island to Lang Tengah Island (10km).

I conceived of the Terengganu Four Swims idea in 2021 after completing my first pioneering swim (Perhentian Channel, which is listed on the MSF Documented Swims).

Originally, my thinking was only confined to Perhentian Channel. I wanted to do the crossing and commemorate the occasion with photos, videos and media coverage. That was why our website and Facebook page are called Perhentian Channel Swim.

But I soon realized the other resort islands in Terengganu were equally suited for marathon swims, at least where distance is concerned.

Now that our team has completed the Redang Channel swim, our confidence has grown. We are now highly motivated to tackle the remaining two of Terengganu Four Swims.



Appendix A: Tides