Gregory J. Hassler

Radio-Controlled Solar Boat Project: Helios 1

I have built a radio-controlled, solar-powered, catamaran-style boat. As a DIY project guy and solar nerd, and inspired by Lukas from the True North Yachts YouTube channel, I decided it would be a fun project to build an RC solar boat from scratch. I call it the Helios 1.

Helios 1 is a deliberate homage to Lukas's 11-meter solar vessel, Helios 11, scaled down to about 1 meter. The hulls are built from foam-core Schedule 40 PVC pipe, with a zero-hull-penetration design. Power comes from a small solar panel through a Victron MPPT charge controller into a 6 Ah LFP battery pack, driving a pair of counter-rotating underwater thrusters controlled by a differential thrust mix on the transmitter.

This page documents everything from hull construction to the RC mixing setup that gives it tank-steering-style control. Below you'll find a video, component and wiring diagrams, a complete parts list with cost breakdown, technical specs, and other information such as radio setup for anyone looking to build something similar.

Helios 1 In The Water:

Final Assembly Overview:

Current status:

Fully operational. Boat has been fully assembled, tested, painted, re-assembled, and has been tuned in multiple sessions.

Helios 1 side view on water Helios 1 close-up on water with clear view of solar panel Rear view on water with ESC speed controllers visible

Helios 1: RC Solar Catamaran Specifications

CategorySpecificationValue
Dimensions
HullLength overall38 in (97 cm)
HullBeam24 in (61 cm)
HullDraft (est.), excluding thrusters (~70% submerged)~3-3/8 in (8.6 cm)
HullFreeboard (waterline to bottom of mounting rails)~2-5/8 in (6.6 cm)
Weights
HullsPontoon weight (pair)~13.5 lb (6.1 kg)
ElectronicsElectronics box, rails, plus ESC & thrusters~8.1 lb (3.7 kg)
Solar PanelPanel and mounting rails~8.9 lb (4.0 kg)
Misc HardwarePVC saddle blocks, inserts, nuts & bolts, etc~2.5 lb (1.1 kg)
All-upTotal weight, ready to run (est.)~33 lb (15.0 kg)
Max BuoyancyPontoons fully submerged (est.)~44 lb (20.0 kg)
Construction
Hull material4-in Schedule 40 foam-core cellular PVC DWV pipeCharlotte 4400 / IPEX series
Hull sealingDome End capsSchedule 40 slip caps, solvent welded
Cross BarsAluminum L-channelRenogy Tilt Rail Kit
Propulsion
ThrustersApisQueen 75mm BrushlessU01 pod thrusters, counter-rotating
ESCsApisQueen PWM (80% throttle cap)45A waterproof
Cruise speedTested~1.7 mph
Top speedTested~2.5 mph
Turn rateTested (~14 in thruster spacing), moving start~40°/sec, 8.9 second 360° spin
Power & Charging
Solar panelRenogy rigid mono, 12V50W
Charge controllerVictron SmartSolar MPPT 75/10Bluetooth monitoring
BatteryTalentcell LF4011, 4S LiFePO4~12.8V nominal, 6Ah
Max PowerContinuous 9 amps @ 12.8v nominal115 Watts (estimated)
Cruise Power2.7 amps @ 12.8v nominal35 Watts (estimated)
Run TimeFull sun >50° elevation angle, Cruise speed∞
Run TimeBattery only, Cruise speed1.5 hour
Radio & Control
TransmitterRadioMaster MT12EdgeTX 2.12.2 Firmware
ReceiverER3C-iExpressLRS
SteeringDifferential thrust, tank mix3 selectable drive modes
RangeExpressLRS Dynamic Power configuredFarther than I can see the boat
TelemetryMain Battery VoltageRxBt via EXT-V sense
Low-voltage alarmReturn-home alarm threshold11.9V
Project
Build startFirst visit to Home Depot for PVCJuly 19, 2026
First launchFirst water test in neighborhood lakeAugust 23, 2026
EnvironmentWater TypeFresh Water Only

Physical Diagrams (simplified)

Front view

Helios 1 front view, main components Front elevation of the Helios 1 RC solar catamaran. Shows the two pontoons at roughly 75 percent submerged, the solar panel raised on riser blocks at the pontoon mount points, the electronics box mounted at the same elevation with its taller top visible behind the panel, and round pod thrusters mounted on each pontoon on a bracket. Waterline Electronics box Victron + battery Solar panel 50W Renogy panel Riser blocks 1.25 in standoff Pontoon hull 4" Foam-Core PVC Thruster Inboard mount

Top view

Helios 1 top view, main components Top-down plan view of the Helios 1 RC solar catamaran, bow at left, stern at right. Shows the two pontoons with rounded bow and stern end caps 38 inches tip to tip, the solar panel mounted just aft of the bow caps, the electronics enclosure just aft of the panel, and the pod thrusters aligned with the hull axis, mounted forward of the stern end caps and roughly half hidden under the pontoon. Bow end cap Dome cap, both hulls Solar panel 22.8" x 19.8" Electronics box 11.4" x 7.5" x 5.5" Thruster ~3 in diameter Stern end cap

Wiring Diagram (single-line)

Helios 1 full wiring diagram Wiring schematic for the Helios 1 RC solar catamaran. The battery is the main power source. Solar panel feeds Victron MPPT, which charges the battery through a charge fuse and switch. The battery feeds out through a load fuse and load switch, to a 3-way XT-60 splitter, which powers the port and starboard ESCs and a UBEC. The UBEC powers the receiver, which sends CH1 and CH2 signal lines to the ESCs and reads an EXT-V sense line from Victron's load output. Electronics enclosure Sealed, watertight CH1 CH2 EXT-V sense MC4 Fuse 10A SW Fuse 10A SW XT XT XT XT XT-60 connector MC4 MC4 solar connector Solar panel Renogy 50W Victron MPPT Charge controller LiFePO4 battery Main power, 12.8V 6Ah Splitter XT-60, 3-way UBEC 5V regulator Receiver ER3C-i RX ESC Port 45A PWM waterproof ESC Stbd 45A PWM waterproof Thruster Port ApisQueen U01 Thruster Stbd ApisQueen U01

BOM:

Category Major Items Approx. Cost
Propulsion ApisQueen U01 thrusters (CW/CCW) + 45A waterproof ESCs $147
Radio & Control RadioMaster MT12 + ER3C-i ExpressLRS receiver $142
Power System 50W Renogy solar panel, Victron MPPT, Talentcell 6Ah battery $152
Hull & Structure 4" foam-core PVC, Schedule 40 end caps, solar mount brackets $125
Enclosure & Hardware Waterproof project box, stainless fasteners, cable glands, switches ~$280
Wiring & Misc XT60 connectors, silicone wire, fuse holders, battery tray, etc. ~$100
Fun Lego Captain Jack Sparrow (crew) $23

Grand Total: $1,051.34

Download full parts list (xlsx)

Radio Setup

Key features of the radio setup on the RadioMaster MT12 Surface Controller: RadioMaster Model Backup File (YML file displayed as plain text)

Thruster wiring reference

Port thruster wiring (Ch 1) - Counter-Clockwise rotation
Yellow to yellow, green to black, blue to red.

Starboard thruster wiring (Ch 2) - Clockwise rotation
Yellow to yellow, green to red, blue to black.


Build Photos

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V2 Thoughts

Upgrades I'm considering for an updated version:
And it all fits in the back of my SUV on a little stand to keep the weight off the thrusters:
Helios 1 in the back of a Rivian R1S cargo area