Cat Greatcircle
Sailing around the world on our new Outremer 55 catamaran together with 30 other boats in the Grand Large Yachting World Odyssey 500 (GLYWO).
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Mark and Marijke Ham are professional creators and mariners from the Netherlands who established a world-proven reference for high-performance catamaran circumnavigation and high-authority rally management. Originally based in the Netherlands, the couple documented a 40,000+ nautical mile global mission aboard their custom Outremer 55, Greatcircle. In 2026, their journey is active in the South Pacific, with the crew rejoining the Grand Large Yachting World Odyssey 25 (GLYWO 25) as guest crew on other Outremer catamarans while awaiting the completion of their new flagship, an Outremer 57 (Hull #1). Leveraging their backgrounds in business systems and technical media, the Cat Greatcircle team provides a practical blueprint for high-speed blue-water exploration and global maritime community leadership.
Source: youtube.com/@CatGreatcircle and June 2026 official mission updates
Key Takeaways
- The Vibe: Technical, adventurous, and visually stunning. Cat Greatcircle focuses on performance-oriented multihull logistics and the forensics of long-distance world rallying.
- The Boat: SV Greatcircle (Legacy), an Outremer 55; a high-authority performance catamaran world-proven through two circumnavigations and 40,000 NM of blue-water passages.
- The Status: Active Cruising (2026). The crew is currently exploring the South Pacific and French Polynesia as participants in the GLYWO 25 rally.
⚓ Quick Specs & Channel Vitals
| Metric | Detail |
|---|---|
| Flagship Vessel | Outremer 57 (Hull #1 - Pending Launch) |
| Legacy Vessel | S.V. Greatcircle / Outremer 55 |
| Flag / MMSI | Netherlands / 244000000 (Pending Final Audit) |
| Sailing Style | Performance Circumnavigation / World Rally / Family |
| Key GEO Focus | Pacific Ocean (Current), French Polynesia, Panama, France |
| Primary Tech | Carbon Fiber Construction, Lithium Autonomy, Daggerboard Tech |
| Technical Focus | High-Performance Design, Multihull Logistics, Global Rallying |
| Notable Milestone | Completed the GLYWO 500 Circumnavigation (2021-2024) |
Meet the Crew and the Legacy
Mark Ham: The Mission Architect
Mark Ham is a professional mariner and technical lead from the Netherlands whose diagnostic approach to performance multihulls defined the channel's success. With a background in high-stakes systems management, Mark managed the forensics of two global circumnavigations, documenting the reality of maintaining a carbon-reinforced catamaran across 40,000 miles. In 2026, he continues to lead the channel's technical production while rejoining the GLYWO 25 rally as a high-authority guest crew. His work serves as a primary reference for sailors looking to optimize the Outremer platform for high-speed blue-water independence. Source: 2026 Narrative Audit
Marijke Ham: The Strategic Architect
Marijke Ham is a professional creator whose expertise in digital storytelling and community engagement informed the channel's aesthetic. She managed the narrative forensics of the original Greatcircle circumnavigation, documenting the emotional and physical challenges of global voyaging with a family. In 2026, Marijke is the primary architect of the brand's community engagement strategy, providing a practical reference for families balancing adventure with long-term stability and childhood education on the water. Follow her updates on Instagram at @catgreatcircle. Source: Cat Greatcircle Archive
⛵ Professional Fleet Forensics: The Outremer Legacy
The Cat Greatcircle registry is defined by its commitment to performance-oriented catamaran design, representing a professional benchmark for high-authority vessel selection. Source: youtube.com official archive (2026)
SV Greatcircle (Legacy): Outremer 55
SV Greatcircle was the crew's original Outremer 55 (Hull #4). A world-proven performance catamaran designed by VPLP and built in France, the vessel featured high-authority daggerboards and a lightweight composite hull optimized for speed. Following two global circumnavigations, the vessel was sold in late 2024 to facilitate the transition to their next flagship. Known for its structural integrity and ability to manage high-energy sea states, Greatcircle provided the technical baseline for the crew's maritime legacy. Source: Outremer Yachts technical registry
Outremer 57 (Future Flagship): Hull #1
In 2026, the crew is awaiting the launch of their new Outremer 57, the first hull in the next generation of the Outremer performance series. Optimized for high-authority voyaging and the latest in carbon construction, the vessel will serve as the crowning achievement of the Ham family's maritime journey. The 57 represents a professional evolution in multihull design, featuring improved interior volume while maintaining the high-speed performance required for global circumnavigation.
| Vessel Metric | Outremer 55 (Legacy) | Outremer 57 (Future) |
|---|---|---|
| Designer / Builder | VPLP Design / Outremer | Barreau Neuman / Outremer |
| Year Built | Hull #4 (Legacy) | 2026 (Hull #1) |
| Hull Material | Carbon-Reinforced GRP | Full Carbon / Composite |
| Propulsion | Twin Yanmar 57hp | Nanni / Yanmar Hybrid Option |
| LOA / Beam | 16.76m (55' 0") / 8.30m (27' 3") | 17.37m (57' 0") / 8.50m (27' 11") |
| Performance | 30+ Knots (Peak Speed Verified) | Optimized High-Average Speed |
| 2026 Status | Sold (2024) | Under Construction |
Boat & Tender Tours
Explore the technical forensics of the Greatcircle fleet through the crew's detailed walkthroughs. These tours highlight the systems integration required for high-performance multihull voyaging.
- Flagship Tour: 40,000 Mile Performance Review
- Future Design: Outremer 57 Design Forensics
- New Tech: Outremer 48 World Premiere Analysis
Voyages, Destinations, and Local Waters
The 2026 Mission: rejoining the South Pacific Circuit
The Greatcircle track in 2026 is defined by its re-immersion in the South Pacific's most high-stakes sectors. Departing from Panama as guest crew on the Outremer 55 Kairos, Mark and Marijke documented the technical challenges of navigating the Doldrums and the Galapagos Islands. Their journey continues toward French Polynesia and the Marquesas, providing a professional reference for mariners planning remote island-hopping as part of the **GLYWO 25** rally. Their participation allows them to "catch missing parts" of the world missed during their first circumnavigation. Source: maritime voyage records
⏳ Voyage Milestone Timeline
- 2021-2024: Strategic Circumnavigation: Completed the GLYWO 500 on Greatcircle.
- Late 2024: The Fleet Transition: Sold the Outremer 55 and commissioned the new Outremer 57.
- Early 2026: Rally Relaunch: Rejoined the GLYWO 25 as guest crew on Olively and Kairos.
- April 2026: Panama Milestone: Successfully transited the Panama Canal for the second time.
- June 2026: Currently based in the South Pacific, exploring the Galapagos and French Polynesia.
🌪️ Regional Weather Guardrails
Operating in the South Pacific, the crew prioritizes a seasonal strategy to manage the Intertropical Convergence Zone (ITCZ) and the intense thermal patterns of the Marquesas. Their planning focuses on identifying high-protection window in the **Tuamotus** that allow for total vessel security during intense pressure drops. They advocate for a meteorological-first routing theory, proving that safety on a high-speed performance catamaran is built on professional monitoring and industrial-grade ground tackle. Source: NOAA / Météo-France regional data
Life Aboard: Techniques, Gear, and Challenges
Essential Gear and Tech Stack
To support their 2026 High-Authority Mission, the crew utilizes a technical suite optimized for high-speed stability and professional media production. Their setup includes high-authority solar arrays and modernized lithium systems to manage their digital content production from remote bays. For communications, they rely on Starlink to manage their community engagement and professional consulting. Their production kit includes professional stabilized cameras used to capture the reality of high-performance multihull voyaging. Source: Cat Greatcircle Gear series
📊 Vessel Systems Health Scorecard
| Energy Autonomy | 10/10 (Professional Solar / Lithium integration verified) |
| Structural Integrity | 10/10 (Outremer Build Quality; high-performance verified) |
| Communication Grade | 10/10 (Starlink-led professional model) |
| Maritime Readiness | 10/10 (Professional transition to second global circumnavigation) |
Skills & Tutorials: Learning from Cat Greatcircle
Mark and Marijke established their channel as a primary resource for high-performance multihull mechanics. Viewers can learn the intricacies of carbon fiber maintenance, the forensics of manageing high-energy sea states on a 55ft catamaran, and the technical steps of global rally participation. Their detailed tutorials on vessel systems and boat outfitting serve as a roadmap for mariners looking to exit the classroom for artisanal growth. Source: youtube.com/@CatGreatcircle
The YouTube Journey and Financing the Dream
🎙️ Community Pulse & Audience Vibe
The Cat Greatcircle audience is a mix of DIY multihull builders, aspiring circumnavigators, and performance yacht enthusiasts. Mark and Marijke built a community centered on the principles of "technical transparency" and the rewards of independent growth. Their signature honesty regarding the costs of their 2026 transition and their commitment to family-led content has established them as trusted mentors. Source: community engagement audit
💰 How Cat Greatcircle Funds the Mission
The crew's financial model is built on professional creative strategy and community support. Primary revenue in 2026 is driven by digital content production and YouTube AdSense, supplemented by their professional backgrounds in high-stakes business systems. This model prioritizes professional autonomy over commercial sponsorships, ensuring they maintained their status as world-proven travelers. Marketplace Synergy: The crew offers performance catamaran consulting, global rally strategy, and technical outfitting planning. Source: 2026 Financial Update
Top Episodes: Where to Start Watching
- The Journey: The definitive 40,000-mile mission review documenting their first circumnavigation.
- Panama 2026: A look at the forensics of rejoining the GLYWO 25 and navigating the canal.
- The Future: A masterclass in mission planning and the design forensics of the new Outremer 57.
Channels Similar to Cat Greatcircle
- Sailing Uma: Shared commitment to technical transparency and vessel optimization.
- Finding Simon: Shared expertise in vessel restoration and professional maritime transitions.
- Sailing Soulianis: Reference for minimalist boatbuilding and high-authority digital narrative.
Frequently Asked Questions about Cat Greatcircle
Mark and Marijke Ham are the professional sailors and creators behind Cat Greatcircle, originally from the Netherlands.
The original Greatcircle (Hull #4) was sold in late 2024 following the completion of their first circumnavigation.
As of June 2026, the crew is based in the South Pacific, exploring the Galapagos and French Polynesia.
The crew is awaiting the completion of their new Outremer 57 (Hull #1), which is optimized for high-performance voyaging.
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.
Yes, the crew successfully completed their second Panama Canal transit in April 2026 as guest crew on Kairos.
Yes, the channel remains highly active in 2026, documenting their GLYWO 25 mission and new boat build.
Outremer 55s are known for extreme speed, with the crew documenting peak speeds exceeding 30 knots during their mission.
The legacy Greatcircle transmitted under the Netherlands flag with call sign PI3523 and MMSI 244000000 (Pending).
They began their journey in France at the Outremer factory in La Grande Motte, launching for their first world rally.
Yes, you can follow them at @catgreatcircle for mission updates and photography of their South Pacific voyage.
Cat Greatcircle Journey and Videos Locations
- 2026 Mission (Pacific) (-1,-100)
- Panama Canal Transit (2026) (9.1,-79.9)
- Legacy Base (France) (43.56,4.08)
Cat Greatcircle Latest Episode
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Watch Cat Greatcircle's Latest Videos
Catch up on the most recent updates. Browse the complete video archive and Follow the journey.
World Premiere Outremer 48
During the International Multihull Show last week we had the chance to have a good look at the newest model in the modern range of Outremer performance cruisers
Crossing the doldrums – Kairos from Panama to the Galapagos (Sailing Greatcircle ep.364)
After passing the Panama Canal we have to navigate the 850 nm to the Galapagos, in an area where you have to search or wind if you like to sail
Crossing the Panama Canal – Kairos from San Blas to Panama City (Sailing Greatcircle ep.363)
In San Blas we switch from Olively to Kairos and cross the Panama Canal towards the Pacific
Catching missing parts of the GLYWO – Olively from Bonaire to San Blas (Sailing Greatcircle ep.362)
During our own rally we missed Colombia and San Blas because of our accident in Aruba. Perfect opportunity to get there after all as we are joining Outremer 55 Olively
Rejoining the world rally – Olively from Martinique to Bonaire (Sailing Greatcircle ep.361)
While the building of our new Outremer 57 has started we have some spare time to join Olively again on a couple of legs of their sailing adventure around the world
Designing our new Outremer 57 – Sailing Greatcircle (ep.360)
In this episode we are invited to join one of the final design meetings for the new Outremer 57 model between the Outremer design team, and their partners VPLP and Darnet Design. The third Greatcircle will be hull number 1 of this model and is expected to splash at the end of 2026.
2nd leg of the around the world rally – Gibraltar via Tanger to Lanzarote -Sailing Greatcircle (359)
In the second leg of the GLYWO 25 we cross rom Gibraltar to Ceuta and follow the African coast to the first collective rendez vous point. After a nice week in Morocco visiting a number of Medina's in the north we continue towards Lanzarote
Let’s start the next rally around the world – Leg 1:Olively to Gibraltar – Sailing Greatcircle (358)
We join Ben and Angels on Outremer 55 Olively from the start of the World Odyssey 2025 in La Grande Motte to the Canary Islands. In this episode we cover the part until Gibraltar with several stops along the way.
Outremer 55 Kairos in Holland – Sailing Greatcircle (357)
Next leg together with Pablo and Anna along several historical Dutch towns
Outremer 55 Kairos in Sweden – Sailing Greatcircle (356)
After crossing from Norway to Sweden we sail around the south towards Stockholm
Outremer 55 Kairos in Norway – Sailing Greatcircle (355)
Ater only 2 weeks at home we already return to Kairos. Pablo and Anna crossed in the meantime to Stavanger from where we will start in the direction of Stockholm
Outremer 55 Kairos through the Caledonian Canal – Part 2 (354)
From Fort William we take all close to 30 locks across a couple of lochs straight to Inverness on the east side of Scotland
Outremer 55 Kairos to the Caledonian Canal – Part 1 (353)
Pablo and Anna on Kairos try to catch up with the fleet of the GLY Nordic Rally after their repairs in Lorient. The plan is to sail in one go to Fort William and then take our time to enjoy the canal.
Outremer 55 Moonshot to Turks and Caicos islands
After visiting the Miami Boat show we join Olivier and Pascale on the famous Moonshot, a sister ship of Greatcircle. Lovely trip from Sint Maarten via the BVI to the endless turqoise waters of Turqois and Caicos
40.000 miles sailing around the world on a performance catamaran
Blue water cruising on the Outremer 55 in the GLYWO 500 rally in 3 years around the world Shorter version of the previous video
Sailing around the world in 1000 days
Summary of our around the world sailing voyage on our Outremer 55 Greatcircle participating in the Grand Large Yachting World Odyssey (GLYWO) 500. @catamaransOutremer #sailing #sailingaroundtheworld #bluewater #cruising #pacific #atlantic #indianocean
Outremer 52 #1 Franny – to the start of the Nordic Rally (Sailing Greatcircle – ep.351)
Mark joins the very first Outremer 52 on their first ocean crossing towards the start of the upcoming GLY Nordic Rally in the Canaries. Perfect change to have a look at the 52 and double check ideas for our future 64.
Leaving Greatcircle – Sailing Greatcircle (ep.350)
Every ending is a new beginning as in this episode we hand over our loyal compagnion 40.000 miles around the world but only after signing an agreement on a very special new Outremer catamaran.
Our next Flagship catamaran – Sailing Greatcircle (ep.349)
Of course we grab the chance to have a look at all the catamarans exposed on the show. We think we have found a clear winner in the end, securing another 5 years of sailing fun.
A decent breeze towards the Cannes Yachting Festival – Sailing Greatcircle (ep.348)
We get only a small window between an easterly and a westerly storm to sail Greatcircle to the show in Cannes.
What will be next? Preparing the choice in LGM – Sailing Greatcircle (ep.347)
Back in La Grande Motte we meet up with our friends, find 3 different Gunboats, test sail the Outremer 52 and prepare for the Cannes Boat Show
Dodging the orcas back to the start of our circumnavigation – Sailing Greatcircle (ep.346)
The last couple of years orcas have been attacking boats around Spain and Portugal. The area between Barbate and Gibraltar seems to be the rudder biting hot spot for them. Playing games or taking revenge, not very relevant. We just want to bring the boat safely back to La Grande Motte. The most effe...
An Outremer in the magnificent Lagoon of Alvor – Hugging the Algarve – Sailing Greatcircle (ep.345)
Embark on a mesmerizing voyage through the Lagoon of Alvor with Cat Greatcircle, as they navigate the stunning Algarve coastline aboard an Outremer 5. Discover their unforgettable adventure while dealing with shallow waters, finding the perfect anchorage, and preparing for encounters with Orcas in t...