Can the sail actually be adjusted?

Yes, a small mechanism on the deck lets you change the sail's angle, similar to how a real sailing boat works.

Does the set include any minifigures?

No, the set has no minifigures; the focus is entirely on the functional model itself.

Are the parts useful for other Technic builds?

Yes, many of the 76 unique parts are classic Technic connectors that work well in other constructions too.

Technic

Catamaran

The Catamaran is a LEGO® Technic set that builds, as the name suggests, a sailing boat with two parallel hulls instead of a single classic hull. With 405 pieces and 76 unique parts, it is built firmly around functional Technic mechanics rather than figures or storytelling. An adjustable sail and a working rudder give it a genuine functional-model feel.

Set number: 42105
Year: 2020
Pieces: 405
Minifigures: 0
Theme: Technic
Different parts: 76

What can I build with it?

View the official building instructions at LEGO® ↗

Parts list 76

As BrickLink list (XML)

Import on BrickLink: Wanted → Upload, upload the file (or paste its content), pick a Wanted List and add the parts.

Spare parts (8)

These extra parts come with the set in case one gets lost.

Description

Two hulls instead of one

The twin-hull design that gives a catamaran its name is recreated here through two parallel floats connected by a central deck, giving the model more stability on water than a single-hulled boat would. That deck carries the sail and rudder mechanism, so the whole model works as a self-contained functional build rather than just a static shape. This layout sets the set apart from most other LEGO® Technic vehicles, which tend to focus on land or construction machinery instead.

An adjustable sail and rudder

A small mechanism on the deck lets you adjust the angle of the sail, while a separate rudder at the stern sets the direction, both modelled on how a real sailing boat works. These functions make the model interesting beyond just display, inviting you to actually try the mechanics out, whether in a bathtub or on a lake. For Technic fans who prefer working mechanics over classic brick building, this is the set's defining feature, and one that is easy to demonstrate to others.

Grey tones with a blue accent

Black and the two shades of grey form the model's core structure, while blue picks out the sail and other details for a maritime colour feel. Among the 76 unique parts are plenty of classic Technic connectors and axles that work just as well in other builds well outside the boat theme. The parts list on this page breaks down exactly which Technic pieces are included and how often each one appears.

Who this set suits

At 405 pieces, the Catamaran sits in the mid-size range for LEGO® Technic sets and suits anyone who prefers functional models over classic land vehicles. With no minifigures included, the focus stays entirely on mechanics and construction, which makes it particularly appealing to experienced Technic builders. It fits well alongside an existing Technic collection but also works as a standalone entry point into maritime models.

FAQ

Can the sail actually be adjusted?: Yes, a small mechanism on the deck lets you change the sail's angle, similar to how a real sailing boat works.
Does the set include any minifigures?: No, the set has no minifigures; the focus is entirely on the functional model itself.
Are the parts useful for other Technic builds?: Yes, many of the 76 unique parts are classic Technic connectors that work well in other constructions too.