Smash the waves!
Build the Hydroplane Racer

Experience the thrill of high-speed racing with this aerodynamic 180-piece LEGO Technic set. A fun and engaging 2-in-1 build that transforms into a Race Boat!

🏛 Technic
Set #42045

Hydroplane Racer

The Hydroplane Racer is a surprisingly fun little Technic set.

Before you buy

Who it's for
Ages 8+ · Beginner build Perfect for kids and teens interested in learning basic Technic principles
Build
180 pieces · about 1.5 hours Build time is an estimate.
Price
$19.99 list price · 11.1¢ per piece
Availability
Retired at LEGO
★★★☆☆ 3.4 community rating

Generally well-received as a good starter Technic set, though some feel it's a bit simple for experienced builders. The working piston engine is a highlight, but some find the building experience somewhat repetitive.

MSRP
$19.99
Best Price
$21.78
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📝 Our Take

AI-assisted editorial summary, grounded in our LEGO database and public community discussions. How we use AI

The Hydroplane Racer is a surprisingly fun little Technic set. Despite its small size, it packs in some clever engineering and a vibrant color scheme that makes it stand out. The working piston engine is a delightful touch, showcasing the core principles of Technic in an accessible way.

This set is perfect for younger builders or anyone looking for a quick and satisfying Technic build. With under 200 pieces, it's a great introduction to gears, axles, and other fundamental Technic elements. The alternate build as a race boat adds to the play value and learning opportunities.

Skip this if you're an experienced Technic builder looking for a complex and challenging project. This set is geared towards beginners, so you might find it too simplistic. Consider larger Technic sets with more intricate mechanisms for a more engaging experience.

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🧱 Building Experience

AI-assisted build estimate, grounded in our LEGO database and public community discussions. How we use AI
🧩
180
Pieces
⏱
1.5h
Estimated Build Time
📊
Beginner
Difficulty
👤
8-14
Ages
Build Highlights:
  • Simple and straightforward construction
  • Working piston engine mechanism
  • Introduction to gears and axles
  • Alternate build provides additional play value

📈 Investment Analysis

AI-assisted investment analysis, grounded in our LEGO database and public community discussions. How we use AI
→ Price stable
C+
Investment Grade
⏳ Retired
The Hydroplane Racer, being a smaller, retired Technic set, presents a mixed investment profile. Its initial low MSRP makes it accessible, but its piece count limits its potential for significant appreciation. The Technic theme generally holds value, especially for sets with unique parts or functions. While not a high-return investment, it may see modest gains over time, especially if kept sealed and in excellent condition. However, larger, more complex Technic sets tend to perform better in the long run.

Not Financial Advice: Content is for educational purposes only. Past performance doesn't guarantee future results. Full disclaimer

📖 About This Set

Thunder over the ocean with the Hydroplane Racer!

Smash water speed records with this amazing, aerodynamic 2-in-1 model, featuring massive sponsons, large cockpit and a blue and white color scheme with sporty black-and-white checkered racing stickers. Maneuver this powerful machine to the starting line and see the propeller and engine pistons spring into action. Now get ready to race! When you feel like another building challenge, rebuild it into a high-speed Race Boat. Interactive, 3D Digital LEGO® Building Instructions app available online, for both models!

  • Features a unique aerodynamic design with huge sponsons, large cockpit, detailed engine with moving pistons and a spinning propeller.
  • Check out the blue and white color scheme with sporty black-and-white checkered racing stickers.
  • Maneuver the Hydroplane Racer and see the engine and propeller spring to life.
  • This LEGO Technic model is designed to provide an immersive and rewarding building experience.
  • Appropriate for children aged 8 to 14.
  • Interactive, 3D Digital LEGO Building Instructions app available online for both A and B models.
  • 2-in-1 model: rebuilds into a Race Boat.
  • Hydroplane Racer measures over 2” (6cm) high, 9” (23cm) long and 5” (13cm) wide.
  • Race Boat measures over 2” (6cm) high, 8” (21cm) long and 3” (10cm) wide.

⚖ Compare Similar Sets

Compared to other small Technic sets, the Hydroplane Racer offers a good introduction to basic mechanisms. Sets like the Getaway Racer (42046-1) provide a similar building experience at a comparable price point. However, the Hydroplane Racer's vibrant color scheme and working piston engine might appeal more to some builders. For those seeking a slightly more complex build, the Quad Bike (42034-1) offers additional challenges.

📦 Parts Inventory

Official piece count
180
Parts cataloged in this inventory
59 unique parts, 180 pieces
Technic Gear 8 Tooth [Reinforced] Technic Gear 8 To...
Part #: 10928 1× Dark Bluish Gray
Technic Axle 5 with Stop Technic Axle 5 wi...
Part #: 15462 1× Dark Tan
Technic Axle Pin 3L with Friction Ridges Lengthwise and 2L Axle Technic Axle Pin ...
Part #: 18651 1× Black
Technic Panel Curved 3 x 13 Technic Panel Cur...
Part #: 18944 1× Blue
Technic Panel Curved and Bent 6 x 3 Technic Panel Cur...
Part #: 24116 2× Blue
Sticker Sheet for Set 42045-1 Sticker Sheet for...
Part #: 24732 1× [No Color/Any Color]
Plate Round 2 x 2 with Rounded Bottom [Boat Stud] Plate Round 2 x 2...
Part #: 2654 2× Blue
Technic Pin with Friction Ridges Lengthwise and Center Slots Technic Pin with ...
Part #: 2780 30× Black
Technic Wedge Belt Wheel Tire Technic Wedge Bel...
Part #: 2815 2× Black
Technic Engine Cylinder without Side Slots, with Bottom Slots Technic Engine Cy...
Part #: 2850b 4× Light Bluish Gray
Technic Engine Piston Round Technic Engine Pi...
Part #: 2851 4× Yellow
Technic Engine Connecting Rod Technic Engine Co...
Part #: 2852 4× Light Bluish Gray
Technic Engine Crankshaft Technic Engine Cr...
Part #: 2853 2× Yellow
Technic Engine Crankshaft Center Technic Engine Cr...
Part #: 2854 3× Tan
Technic Brick 1 x 2 [2 Pin Holes] Technic Brick 1 x...
Part #: 32000 2× Black
Technic Pin 3/4 Technic Pin 3/4
Part #: 32002 1× Tan
Technic Axle and Pin Connector Angled #1 Technic Axle and ...
Part #: 32013 2× White
Technic Axle Connector with Axle Hole Technic Axle Conn...
Part #: 32039 4× Black
Technic Pin Long with Friction Ridges Lengthwise and Stop Bush [3 Lateral Holes, Big Pin Hole] Technic Pin Long ...
Part #: 32054 4× Light Bluish Gray
Technic Beam 3 x 3 L-Shape Thin Technic Beam 3 x ...
Part #: 32056 4× Black
Technic Axle 2 Notched Technic Axle 2 No...
Part #: 32062 7× Red
Technic Axle 5 Technic Axle 5
Part #: 32073 4× Light Bluish Gray
Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced Technic Bush 1/2 ...
Part #: 32123b 6× Yellow
Technic Beam 2 x 4 L-Shape Thick Technic Beam 2 x ...
Part #: 32140 3× White
Technic Beam 2 x 4 L-Shape Thick Technic Beam 2 x ...
Part #: 32140 2× Blue
Technic Axle and Pin Connector Perpendicular 3L with Centre Pin Hole Technic Axle and ...
Part #: 32184 6× Light Bluish Gray
Technic Gear 20 Tooth Bevel Technic Gear 20 T...
Part #: 32198 1× Tan
Technic Gear 12 Tooth Double Bevel Technic Gear 12 T...
Part #: 32270 1× Black
Technic Beam 1 x 4 Thin Technic Beam 1 x ...
Part #: 32449 2× Black
Technic Beam 1 x 3 Thick Technic Beam 1 x ...
Part #: 32523 4× White
Technic Beam 1 x 7 Thick Technic Beam 1 x ...
Part #: 32524 2× Blue
Technic Beam 1 x 11 Thick Technic Beam 1 x ...
Part #: 32525 2× White
Axle Hose, Soft 7L Axle Hose, Soft 7L
Part #: 32580 2× Black
Technic Beam 3 x 0.5 Liftarm with Boss and Pin / Crank Technic Beam 3 x ...
Part #: 33299a 4× Light Bluish Gray
Technic Gear 24 Tooth [New Style with Single Axle Hole] Technic Gear 24 T...
Part #: 3648b 1× Dark Bluish Gray
Technic Axle 4 Technic Axle 4
Part #: 3705 2× Black
Technic Bush Technic Bush
Part #: 3713 1× Light Bluish Gray
Technic Axle Pin without Friction Ridges Lengthwise Technic Axle Pin ...
Part #: 3749 2× Tan
Technic Beam 1 x 13 Thick Technic Beam 1 x ...
Part #: 41239 2× Black
Technic Wedge Belt Wheel [aka Pulley] Technic Wedge Bel...
Part #: 4185 2× Light Bluish Gray
Technic Axle Pin with Friction Ridges Lengthwise Technic Axle Pin ...
Part #: 43093 5× Blue
Technic Axle 7 Technic Axle 7
Part #: 44294 1× Yellow
Technic Axle 3 Technic Axle 3
Part #: 4519 6× Light Bluish Gray
Technic Axle and Pin Connector, Perpendicular with Extension Technic Axle and ...
Part #: 53586 4× Flat Silver
Wheel 31 x 15 Technic, 7 Pin Holes Wheel 31 x 15 Tec...
Part #: 60208 1× White
Propeller 3 Blade 3 Diameter with Axle Cross Propeller 3 Blade...
Part #: 6041 1× Black
Technic Beam 1 x 2 Thick with Pin Hole and Axle Hole Technic Beam 1 x ...
Part #: 60483 3× Dark Bluish Gray
Technic Axle 9 Technic Axle 9
Part #: 60485 1× Light Bluish Gray
Technic Pin Connector Round [Slotted] Technic Pin Conne...
Part #: 62462 1× Light Bluish Gray
Technic Axle and Pin Connector Perpendicular Triple Technic Axle and ...
Part #: 63869 1× Light Bluish Gray
Technic Panel Fairing # 4 Small Smooth Long, Side B Technic Panel Fai...
Part #: 64391 1× White
Technic Panel Fairing #17 Large Smooth, Side A Technic Panel Fai...
Part #: 64392 1× White
Technic Panel Fairing #6 Long Smooth, Side B Technic Panel Fai...
Part #: 64393 1× White
Technic Panel Fairing #5 Long Smooth, Side A Technic Panel Fai...
Part #: 64681 1× White
Technic Panel Fairing #18 Large Smooth, Side B Technic Panel Fai...
Part #: 64682 1× White
Technic Panel Fairing # 3 Small Smooth Long, Side A Technic Panel Fai...
Part #: 64683 1× White
Technic Axle and Pin Connector Perpendicular Technic Axle and ...
Part #: 6536 8× White
Technic Pin Long with Friction Ridges Lengthwise, 2 Center Slots Technic Pin Long ...
Part #: 6558 8× Blue
Technic Beam 1 x 3 Thin Technic Beam 1 x ...
Part #: 6632 2× White
Technic Axle 4 with Stop Technic Axle 4 wi...
Part #: 87083 1× Dark Bluish Gray
The set includes a good selection of Technic pins and connectors, useful for MOC builders looking to add functionality to their creations. The light bluish gray engine components are also valuable for creating custom engine designs.

💎 Notable Parts

Light Bluish Gray Technic Engine Connecting Rod (4x) $0.60
Yellow Technic Engine Piston Round (4x) $0.80
Light Bluish Gray Technic Engine Cylinder without Side Slots, with Bottom Slots (4x) $0.60
Est. BrickLink Part Value
$2.00

💡 MOC Potential

🚗 Small off-road buggy with suspension
🚗 Miniature tractor with working steering
🤖 Simple walking robot with gear-driven legs

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📖 Building Instructions 4

Hydroplane Racer Instructions
BI 3004 60, 42045 1/2 V29
Download PDF
Hydroplane Racer Instructions
BI 3004 60, 42045 1/2 V39
Download PDF
Hydroplane Racer Instructions
BI 3004/48, 42045 2/2 V29
Download PDF
Hydroplane Racer Instructions
BI 3004/48, 42045 2/2 V39
Download PDF

Charts Inventory Statistics

59
Unique Parts
180
Official Piece Count
180
Cataloged Inventory Pieces
0
Minifigures
4
Spare Parts
Inventory Version: 1

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