Who are Mark and Marijke Ham?

Mark and Marijke Ham are the professional sailors and creators behind Cat Greatcircle, originally from the Netherlands.

What happened to their Outremer 55?

The original Greatcircle (Hull #4) was sold in late 2024 following the completion of their first circumnavigation.

Where is Cat Greatcircle in 2026?

As of June 2026, the crew is based in the South Pacific, exploring the Galapagos and French Polynesia.

What is their new boat?

The crew is awaiting the completion of their new Outremer 57 (Hull #1), which is optimized for high-performance voyaging.

How do they fund their travels?

Their mission is funded through digital content production, YouTube AdSense revenue, and professional consulting services.

GLYWO stands for the Grand Large Yachting World Odyssey, a global rally organized by the owners of Outremer and Garcia.

Did they sail through the Panama Canal?

Yes, the crew successfully completed their second Panama Canal transit in April 2026 as guest crew on Kairos.

Is the channel still active in 2026?

Yes, the channel remains highly active in 2026, documenting their GLYWO 25 mission and new boat build.

How fast can an Outremer 55 go?

Outremer 55s are known for extreme speed, with the crew documenting peak speeds exceeding 30 knots during their mission.

What is the boat's MMSI number?

The legacy Greatcircle transmitted under the Netherlands flag with call sign PI3523 and MMSI 244000000 (Pending).

Where did they start their journey?

They began their journey in France at the Outremer factory in La Grande Motte, launching for their first world rally.

Can I follow them on Instagram?

Yes, you can follow them at @catgreatcircle for mission updates and photography of their South Pacific voyage.

Cat Greatcircle

Sailing Cat Greatcircle – Overview 2017 Part 4 : Ionian Islands Greece (ep. 41 – 46)

Summary of our travels on Lagoon 52S Greatcircle from February to November 2017. The overview focusses on the route and the anchorages and gives a link to the individual episodes.

Dec 25, 2017
Language: EN
Play Time: 00:24:12

Cat Greatcircle

Sailing Cat Greatcircle – Overview 2017 Part 3 : Corsica to Sicily (ep. 32 – 40)

Summary of our travels on Lagoon 52S Greatcircle from February to November 2017. The overview focusses on the route and the anchorages and gives a link to the individual episodes.

Dec 21, 2017
Language: EN
Play Time: 00:25:01

Cat Greatcircle

Sailing Cat Greatcircle – Overview 2017 Part 2 : French and Italian Rivieras (ep. 23 – 31)

Summary of our travels on Lagoon 52S Greatcircle from February to November 2017. The overview focusses on the route and the anchorages and gives a link to the individual episodes.

Dec 16, 2017
Language: EN
Play Time: 00:18:59

Cat Greatcircle

Sailing Cat Greatcircle – Overview 2017 Part 1 : Bordeaux – La Grande Motte (ep. 10 – 22)

Summary of our travels on Lagoon 52S Greatcircle from February to November 2017. The overview focusses on the route and the anchorages and gives a link to the individual episodes.

Dec 11, 2017
Language: EN
Play Time: 00:16:28

Cat Greatcircle

Sailing Greatcircle – Out of the water (ep.57)

Last couple of legs for this year from Yerakas on Peleponnesos to Aegina where we take Greatcircle ashore at Planaco shipyard.

Nov 12, 2017
Language: EN
Play Time: 00:13:01

Cat Greatcircle

Sailing Greatcircle – Monemvasia (ep.56)

Caught another tuna at the second attempt, on our way from Chania to Monemvasia. Finally got to use our electric foldable bikes from a bay north of Monemvasia to the old town. Small hop to Yerakas before we head towards our final destination for this year Aegina.

Nov 03, 2017
Language: EN
Play Time: 00:08:13

Cat Greatcircle

Sailing Greatcircle – Chania Too mobile (ep.55b)

All attempts to get to Chamvousa and Balos fail, so we're stuck in Chania. No worries, nice town and lots of both old and new friends, before we head back to the mainland. Sailing SeaTramp has an own YouTube channel :

Nov 01, 2017
Language: EN
Play Time: 00:12:54

Cat Greatcircle

Sailing Greatcircle – Chania Too (ep.55)

All attempts to get to Chamvousa and Balos fail, so we're stuck in Chania. No worries, nice town and lots of both old and new friends, before we head back to the mainland. Sailing SeaTramp has an own YouTube channel : (apparently India Arie also doesn't like to be on mobile devices, mob...

Oct 31, 2017
Language: EN
Play Time: 00:13:25

Cat Greatcircle

Sailing Greatcircle – Chania (ep.54)

We stay a while in the lovely and lively town of Chania, formerly the capital of Crete.

Oct 22, 2017
Language: EN
Play Time: 00:09:36

Cat Greatcircle

Sailing Greatcircle – Rethymno and Santorini mobile (ep.53b)

We sail from Iraklion to Rethymno where we explore parts of Crete together with our friends Martin & Rudy who are on holiday on the island. We didn't have the chance to visit the villages on Santorini when we where there earlier and decide to make up for that by taking the fast ferry from R...

Oct 16, 2017
Language: EN
Play Time: 00:11:02

Cat Greatcircle

Sailing Greatcircle – Rethymno and Santorini (ep.53)

We sail from Iraklion to Rethymno where we explore parts of Crete together with our friends Martin & Rudy who are on holiday on the island. We didn't have the chance to visit the villages on Santorini when we where there earlier and decide to make up for that by taking the fast ferry

Oct 15, 2017
Language: EN
Play Time: 00:10:48

Cat Greatcircle

Sailing Greatcircle – Crete : Agios Nikolaos to Heraklion (ep.52)

Karin & Rens join us on Crete from Agios Nikolaos to the harbour of Heraklion

Oct 12, 2017
Language: EN
Play Time: 00:09:21

Cat Greatcircle

Sailing Greatcircle – Santorini to Crete (ep.51)

More wind will make it impossible to stay on Santorini. John & Serena join us by dinghy in Oia, and we sail back north to Ios. A couple of days later we're able to sail the 80 miles straight to Crete where we visit Dia island, Spinalonga and Agios Nikolaos

Oct 04, 2017
Language: EN
Play Time: 00:19:35

Cat Greatcircle

Sailing Greatcircle – Cyclades (ep.50)

Nice tuna on our way to Kithnos, afterwards via Paros and Ios to the challenging harbour of Vlikhadia on the south of Thyra / Santorini

Sep 27, 2017
Language: EN
Play Time: 00:15:29

Cat Greatcircle

Sailing Greatcircle – Astrous to Poros (ep.49)

Now high season is behind us the beautiful islands of Spetses and Hydra are a better option. Before we head to the Cyclades we moor at Poros again to meet friends and repair the water maker.

Sep 23, 2017
Language: EN
Play Time: 00:13:56

Cat Greatcircle

Sailing Greatcircle – Poros to Astros (ep.48b mobile)

After passing through the Corinth Canal we sail via Poros and Hydra to Astrous

Sep 18, 2017
Language: EN
Play Time: 00:16:23

Cat Greatcircle

Sailing Greatcircle – Poros to Astros (ep.48)

Once through the Corinth Canal we continue across the Saronic Gulf to Poros, Hydra, Ermioni into the Argolian Gulf where we visit Porto Heli, Koiladia and Astros. For mobile devices you might need to watch the mobile version 48b.

Sep 17, 2017
Language: EN
Play Time: 00:16:23

Cat Greatcircle

Sailing Greatcircle – Corinth Canal (ep 47b mobile version)

Sailing from the Ionian Sea trough the Corinth Canal. Changed the audio, should work on mobile devices as well.

Sep 11, 2017
Language: EN
Play Time: 00:16:22

Cat Greatcircle

Sailing Greatcircle – Corinth Canal (ep.47)

Back on Greatcircle we leave the Ionian Sea and pass the famous Corinth Canal. In case of problems on a mobile device, see ep. 47b

Sep 11, 2017
Language: EN
Play Time: 00:17:00

Cat Greatcircle

Sailing Greatcircle – Kitesurfing from the Cat (ep.46)

Kjeld tried to teach me to kite in Bonaire in episode 9. Now he's back together with his Ilse to try again, this time straight from Greatcircle. As I am still a beginner I have included some footage of Kjeld showing off.

Aug 30, 2017
Language: EN
Play Time: 00:22:58

Cat Greatcircle

Sailing Greatcircle – Kefalonia to Preveza (ep.45)

Nice anchorages on Kefalonia and Lefkas on our way to Cleopatra Marina in Preveza

Aug 17, 2017
Language: EN
Play Time: 00:16:59

Cat Greatcircle

Sailing Greatcircle – Zakynthos to Kefalonia (ep.44)

Our friends join us in Limni Keri for another tour of Zakynthos before we cross from (a way too busy) Ship Wreck Bay to Kefalonia

Aug 11, 2017
Language: EN
Play Time: 00:19:12

Cat Greatcircle

Sailing Greatcircle – Zakynthos : Limni Keri (ep.43)

Taking is easy for a couple of days in the shallow bay of Keri on the south side of Zakynthos.

Aug 03, 2017
Language: EN
Play Time: 00:12:54

Cat Greatcircle

Sailing Greatcircle – Ship Wreck on Zakynthos (ep.42)

Sailing around Zakynthos and its magnificent blue bays on the west coast. Seems we were lucky there was some swell in Ship Wreck so there was plenty of room to enjoy it.

Jul 27, 2017
Language: EN
Play Time: 00:17:30

Cat Greatcircle – Page 15

Watch Cat Greatcircle's Latest Videos

Sailing Cat Greatcircle – Overview 2017 Part 4 : Ionian Islands Greece (ep. 41 – 46)

Sailing Cat Greatcircle – Overview 2017 Part 3 : Corsica to Sicily (ep. 32 – 40)

Sailing Cat Greatcircle – Overview 2017 Part 2 : French and Italian Rivieras (ep. 23 – 31)

Sailing Cat Greatcircle – Overview 2017 Part 1 : Bordeaux – La Grande Motte (ep. 10 – 22)

Sailing Greatcircle – Out of the water (ep.57)

Sailing Greatcircle – Monemvasia (ep.56)

Sailing Greatcircle – Chania Too mobile (ep.55b)

Sailing Greatcircle – Chania Too (ep.55)

Sailing Greatcircle – Chania (ep.54)

Sailing Greatcircle – Rethymno and Santorini mobile (ep.53b)

Sailing Greatcircle – Rethymno and Santorini (ep.53)

Sailing Greatcircle – Crete : Agios Nikolaos to Heraklion (ep.52)

Sailing Greatcircle – Santorini to Crete (ep.51)

Sailing Greatcircle – Cyclades (ep.50)

Sailing Greatcircle – Astrous to Poros (ep.49)

Sailing Greatcircle – Poros to Astros (ep.48b mobile)

Sailing Greatcircle – Poros to Astros (ep.48)

Sailing Greatcircle – Corinth Canal (ep 47b mobile version)

Sailing Greatcircle – Corinth Canal (ep.47)

Sailing Greatcircle – Kitesurfing from the Cat (ep.46)

Sailing Greatcircle – Kefalonia to Preveza (ep.45)

Sailing Greatcircle – Zakynthos to Kefalonia (ep.44)

Sailing Greatcircle – Zakynthos : Limni Keri (ep.43)

Sailing Greatcircle – Ship Wreck on Zakynthos (ep.42)

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