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

Unfinished business in Milos – Sailing Greatcircle (ep.119)

Last year we had to rush back from Milos after Mark ruptured his tendon saving the bike. We hadn't even have time to visit the white cliffs so it should be worthwhile to give it another try. Via Planaco, where the engines were serviced, and Kythnos we sail over there.

Jun 20, 2019
Language: NL
Play Time: 00:16:53

Cat Greatcircle

The Saronic Gulf revisited – Sailing Greatcircle (ep.118)

We sail a couple of short legs from Poros towards Athens airport from where Sander will fly back to Holland and visit Alpha sails on the way back in Alimos to repair the lazy bag again. Waiting for the right weather window for engine maintenance at Planaco we spend some time in Poros, Hydra and Agki...

Jun 13, 2019
Language: NL
Play Time: 00:16:45

Cat Greatcircle

Advanced tacking Ermioni to Poros – Sailing Greatcircle (ep.117)

We have reach the Saronic Gulf again where we sail from Ermioni to Poros to meet Sander and the Tama crew plus family

Jun 06, 2019
Language: NL
Play Time: 00:13:46

Cat Greatcircle

Peloponnesos, Greece – Monemvasia to Ermioni – Sailing Greatcircle (ep.116)

We're anchored together with a 52F in south mainland of Greece in the bay at Monemvasia before we both sail north to Kyparissa. We cross towards the Saronic Gulf to finalize are tour around the Peloponnesos.

May 30, 2019
Language: NL
Play Time: 00:17:01

Cat Greatcircle

Peloponnesos, Greece – Gythion to Monemvasia – Sailing Greatcircle (ep.115)

After hiding for the storm in Gythion, the old port of the Spartans, we cross the gulf towards Plytra. Via the beautiful turquoise Frangos bay in the south of Elafonisos we round the evil Cape Maléas towards the old Byzantium city of Monemvasia.

May 23, 2019
Language: NL
Play Time: 00:15:05

Cat Greatcircle

Peloponnesos, Greece – Koroni to Gythion – Sailing Greatcircle (ep.114)

From Koroni we cross the Gulf of Messinia towards the Mani peninsula and the snow capped mountains on that side of the Gulf. We visit Limeni and the Diros caves before we go around Cape Tainaro to Porto Kayio and further up to Gythion.

May 16, 2019
Language: NL
Play Time: 00:18:32

Cat Greatcircle

Peloponnesos, Greece – Pilos to Koroni – Sailing Greatcircle (ep.113)

After crossing from Sicily to Greece we spend a couple of days in Pylos together with Sailing Exodos before going south to explore the Peloponnesos.

May 09, 2019
Language: NL
Play Time: 00:15:06

Cat Greatcircle

Sailing, sailing & sailing – Sicily to Greece – Sailing Greatcircle (ep.112)

Good news if you also prefer sailing images over old stones, processions and trying to be a handy man. This episode is all about sailing as we cross from Licata in Sicily towards Pylos in Greece. About 400 Nm in 60 hours with mostly favourable winds and a little help from our friends Sander & Ni...

May 02, 2019
Language: NL
Play Time: 00:18:04

Cat Greatcircle

Finally on our way to Greece – Sailing Greatcircle (ep.111)

Stormy weather helps us to take the time to attend the Easter processions in Licata before we're finally on our way for the 400 Nm crossing to Greece

Apr 30, 2019
Language: NL
Play Time: 00:14:14

Cat Greatcircle

Goodbye Sicily tour – Sailing Greatcircle (ep.110)

We're still waiting on a spare screen for the sliding roof from one of Lagoon's suppliers, so no way we can head for Greece before we return from a Dutch party. Let's drive around the island together with Robbert & Luuke from Eight and look at some old stones ….

Apr 19, 2019
Language: NL
Play Time: 00:07:19

Cat Greatcircle

Cruising around Malta – Sailing Greatcircle (ep.109)

After crossing from Sicily to Gozo we sail a figure 8 around Gozo and Malta with stops at the Blue Lagoon and St Julian's Bay, a tour in the harbour of Valletta and a last stop in a small bay in the north of Comino before we have another downwind leg back to Licata.

Apr 11, 2019
Language: NL
Play Time: 00:18:18

Cat Greatcircle

Perfect Wingaker conditions to Malta – Sailing Greatcircle (ep.108)

After a first trail at very little wind we now sail the 70 miles behind the Wingaker to Malta. The true wind starts at 10 knots dead downwind and both increases and turns gradually during the day so we have plenty of time to get used to the handling of the new sail.

Apr 04, 2019
Language: NL
Play Time: 00:14:37

Cat Greatcircle

Test and install the wingaker – Sailing Greatcircle (ep.107)

After a couple of stormy days the new 235 m2 Wingaker downwind sail arrives. We install some additional components on the front deck and test the Wingaker for the first time in very light winds.

Mar 27, 2019
Language: NL
Play Time: 00:14:14

Cat Greatcircle

Getting ready for the new season – Sailing Greatcircle (ep.106)

I have to admit that waiting is not my prime virtue. We managed to get back to Greatcircle early March but we still have to wait for stuff before we can sail out again. We try to fill the time as useful as possible and our friends in the marina try their utmost to inspire us with their never ending ...

Mar 20, 2019
Language: NL
Play Time: 00:14:59

Cat Greatcircle

Tobago Cays to Grenada on Seatramp – Sailing Greatcircle (ep.105)

We fly to Barbados to meet Nina & Mario who just crossed the Atlantic Ocean just by themselves on their Seatramp. In Part 2 we arrive at the magnificent Tobago Cays and head south to Grenada before flying back via Barbados. We don’t monetize our videos because we want to use the background musi...

Feb 14, 2019
Language: NL
Play Time: 00:19:39

Cat Greatcircle

Seatramps’ Caribbean Clickbait Part 1 – Sailing Greatcircle (ep.104)

We fly to Barbados to meet Nina & Mario who just crossed the Atlantic Ocean just by themselves on their Seatramp.

Feb 05, 2019
Language: NL
Play Time: 00:16:07

Cat Greatcircle

Sailing Cat Greatcircle Introduction

We actually did it, we registered for ARC 2019 and we're going to cross the Atlantic on our Lagoon 52S. Not a big deal you think? For somebody who desperately wanted to see land at all times it's a major step. Now anything can happen. How did it get to this point? See our intro and the ste...

Jan 18, 2019
Language: EN
Play Time: 00:09:20

Cat Greatcircle

Saona 47 Eight – Barcelona to Sicily 2 – Sailing Greatcircle (ep.103)

We're helping Luuke & Robbert to sail Eight to Greatcircle in Marina di Cala del Sole, Licata, Sicily. In Part 2 we sail from Cagliari to Licata. To be able to connect our Earthmate Live tracking we would appreciate it if you like our Facebook page @CatamaranGreatcircle

Dec 26, 2018
Language: EN
Play Time: 00:12:50

Cat Greatcircle

Saona 47 Eight – Barcelona to Sicily – Sailing Greatcircle (ep.102)

We're helping Luuke & Robbert to sail Eight to Greatcircle in Marina di Cala del Sole, Licata, Sicily. To be able to connect our Earthmate Live tracking we would appreciate it if you like our Facebook page @CatamaranGreatcircle

Dec 24, 2018
Language: EN
Play Time: 00:19:47

Cat Greatcircle

Sailing in Greece – Sailing Greatcircle Overview 2018 – Part 4

Back in Greece after 7 weeks in Montenegro and Croatia for the last two months of this year before mooring Greatcircle in Marina di Cala del Sole (Licata, Sicily). Summary of 2018 episode 95 - 101 showing the route we followed with a reference to the original episodes in the upper right corner.

Dec 18, 2018
Language: EN
Play Time: 00:25:01

Cat Greatcircle

Sailing in Croatia – Sailing Greatcircle Overview 2018 – Part 3

After more than a year in Greece we sail north to Montenegro and Croatia for 7 weeks. Summary of 2018 episode 86 - 95 showing the route we followed with a reference to the original episodes in the upper right corner.

Dec 10, 2018
Language: EN
Play Time: 00:22:01

Cat Greatcircle

Sailing in Greece – Sailing Greatcircle Overview 2018 – Part 2

Greece proves why it's known as one of the best sailing areas of the world. In this part we sail in the Saronic Gulf and the Cyclades before going through the Corinth Canal to the Northern Ionian Sea. Summary of 2018 episode 75 - 85 showing the route we followed with a reference to the origina...

Dec 06, 2018
Language: EN
Play Time: 00:17:45

Cat Greatcircle

Sailing in Greece – Sailing Greatcircle Overview 2018 – Part 1

Greece proves why it's known as one of the best sailing areas of the world. In this part we sail from Athens through the Cyclades to the Dodekanesos and back to the Saronic Sea. Summary of the first 14 episodes of 2018 showing the route we followed with a reference to the original episodes in ...

Nov 30, 2018
Language: EN
Play Time: 00:21:30

Cat Greatcircle

Marina di Cala del Sole – Licata Sicily – Sailing Greatcircle (ep.101)

Preparing Greatcircle for winter in the marina on the south side of Sicily as the storms are passing bye.

Nov 15, 2018
Language: EN
Play Time: 00:20:00

Cat Greatcircle – Page 12

Watch Cat Greatcircle's Latest Videos

Unfinished business in Milos – Sailing Greatcircle (ep.119)

The Saronic Gulf revisited – Sailing Greatcircle (ep.118)

Advanced tacking Ermioni to Poros – Sailing Greatcircle (ep.117)

Peloponnesos, Greece – Monemvasia to Ermioni – Sailing Greatcircle (ep.116)

Peloponnesos, Greece – Gythion to Monemvasia – Sailing Greatcircle (ep.115)

Peloponnesos, Greece – Koroni to Gythion – Sailing Greatcircle (ep.114)

Peloponnesos, Greece – Pilos to Koroni – Sailing Greatcircle (ep.113)

Sailing, sailing & sailing – Sicily to Greece – Sailing Greatcircle (ep.112)

Finally on our way to Greece – Sailing Greatcircle (ep.111)

Goodbye Sicily tour – Sailing Greatcircle (ep.110)

Cruising around Malta – Sailing Greatcircle (ep.109)

Perfect Wingaker conditions to Malta – Sailing Greatcircle (ep.108)

Test and install the wingaker – Sailing Greatcircle (ep.107)

Getting ready for the new season – Sailing Greatcircle (ep.106)

Tobago Cays to Grenada on Seatramp – Sailing Greatcircle (ep.105)

Seatramps’ Caribbean Clickbait Part 1 – Sailing Greatcircle (ep.104)

Sailing Cat Greatcircle Introduction

Saona 47 Eight – Barcelona to Sicily 2 – Sailing Greatcircle (ep.103)

Saona 47 Eight – Barcelona to Sicily – Sailing Greatcircle (ep.102)

Sailing in Greece – Sailing Greatcircle Overview 2018 – Part 4

Sailing in Croatia – Sailing Greatcircle Overview 2018 – Part 3

Sailing in Greece – Sailing Greatcircle Overview 2018 – Part 2

Sailing in Greece – Sailing Greatcircle Overview 2018 – Part 1

Marina di Cala del Sole – Licata Sicily – Sailing Greatcircle (ep.101)

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