Sailone - Microtransat 2026 Questions

[Sophie Brookes]

Hi everyone,

I'm part of Sailone, a 3-person student team from Portugal hoping to compete in MicroTransat 2026. Our vessel is a 2.1m autonomous sailboat currently in the build phase, with sea trials planned from July onwards off Setúbal.

We're running a Pixhawk with ArduPilot firmware, an ESP32 for motor PID and wind vane, and a Raspberry Pi Zero 2W for data logging and satellite comms via RockBLOCK Iridium. We're also integrating oceanographic sensors in collaboration with Instituto Superior Técnico.

We'd love to hear from anyone who's been through this before, particularly around:
- ArduPilot tuning for sail and rudder control
- Surviving real sea conditions with autonomous systems
- Anything you wish you'd known before your first offshore trial

We also have three specific challenges we're working through right now and would really appreciate any input:

1. Keel placement — We're still finalising ballast and keel position. How did you approach the trade-off between righting moment and drag? Any rules of thumb for a hull this size?

2. Rudder shaft watertightness & seaweed — We want to keep the rudder shaft completely watertight while also avoiding fouling from seaweed entanglement. What sealing method worked for you, and did you use any geometry tricks (angled leading edge, weed deflectors) to deal with debris?

3. Solar panel configuration — We're trying to optimise panel placement for a vessel that will heel and change heading constantly. Fixed flat mount, angled, or a mix? Did you find one layout significantly outperformed others in practice?

Happy to share more details about the build. Our project page is sailone.org if you'd like to take a look.

Thanks in advance - any advice is genuinely appreciated.

Sophie
Sailone Team

[Georg Niggli]

Hello! I'm Georg from ETH Zürich currently founding our universities Microtransat Team.

I don't have any experinece with offshore trails as I did not do any. 

For point three I'm currently designing and simulating MPPTs optimized for a quick change of solar performance. (with a tuned d term so they react fast) as most of the affordable off the shelf components are not quick enough. The Power point will always considerably drag. I think that the panel configuration is thus not so critical but what matters is that the serial strings that you have are not to long. As partial shadow will be an issue with the sail. I'm thus desining an MPPT in boost configuartion instead of buck.

I can post more as soon as I'm further with the design. 

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Von: microt...@googlegroups.com <microt...@googlegroups.com> im Auftrag von Sophie Brookes <sophieb...@gmail.com>
Gesendet: Wednesday, June 10, 2026 5:00:24 PM
An: microt...@googlegroups.com <microt...@googlegroups.com>
Betreff: [microtransat] Sailone - Microtransat 2026 Questions

 

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[Robin Lovelock on robin@gpss.co.uk]

Hi Sophie & Georg. Welcome to Microtransat.

You may get some useful information on Snoopy's pages, including what to do (like test on a lake first) and not to do (forget to get enough spares of products used :-)

My "Snoopy" page is on http://www.gpss.co.uk/autop.htm - linked to many others.

Try not to fall off your chairs laughing or going to sleep ;-)

Take Care - and don't get caught ;-)

Robin Lovelock in Sunninghill - and Snoopy :-)

http://www.gpss.co.uk & http://www.nhscare.info & http://www.gpshobby.info 

To view this discussion, visit https://groups.google.com/d/msgid/microtransat/AM9PR09MB4866E3F5986B586E12EE1D20A61A2%40AM9PR09MB4866.eurprd09.prod.outlook.com.