Vetus BOW3512E Bow Thruster 35 kgf
#1 in Under 45 kgfFull review
A light, long-running thruster for a 20 to 30 ft boat with a 150 mm tunnel. A Sleipner SE40 gives more thrust for less.
Fisheries Supply $1,786.04 eBay$1,786.04
The Vetus BOW3512E Bow Thruster 35 kgf is the better bow thruster overall, rated 3.8 to 3.6. The Vetus BOW3512E Bow Thruster 35 kgf leads on efficiency and run time. The Sleipner SE40 Tunnel Thruster 12V wins on value and weight. The Sleipner SE40 Tunnel Thruster 12V costs $336.04 less ($1,450 vs $1,786.04).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases. As an eBay Partner, we may be compensated if you make a purchase.
Sleipner SE40 Tunnel Thruster 12V
#2 in Under 45 kgfFull review
A strong value pick for a 26 to 34 ft boat: about $36 per kgf from a compact unit. Check that your battery bank can feed 315 A.
Amazon $1,450 eBay$1,450
Which should you buy?
- Choose the Vetus BOW3512E Bow Thruster 35 kgf for efficiency (23.3 kgf per kW (35 kgf, 1.5 kW) vs 18.2 kgf per kW (40 kgf, 2.2 kW)) and run time (4 minutes continuous vs 3 minutes continuous).
- Choose the Sleipner SE40 Tunnel Thruster 12V for value ($36.25 per kgf ($1,450, 40 kgf) vs $51.03 per kgf ($1,786.04, 35 kgf)) and weight (4 kgf per kg (40 kgf, 10 kg) vs 2.9 kgf per kg (35 kgf, 12 kg)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every under 45 kgf bow thruster; a clear win is highlighted. How we rank explains each one.
| Factor weight | Vetus BOW3512E Bow Thruster 35 kgf | Sleipner SE40 Tunnel Thruster 12V |
|---|---|---|
| Overall rating | 3.8/5 | 3.6/5 |
| Value 40% | 52 $51.03 per kgf ($1,786.04, 35 kgf) | 75 $36.25 per kgf ($1,450, 40 kgf) |
| Efficiency 25% | 100 23.3 kgf per kW (35 kgf, 1.5 kW) | 60 18.2 kgf per kW (40 kgf, 2.2 kW) |
| Run time 25% | 67 4 minutes continuous | 33 3 minutes continuous |
| Weight 10% | 31 2.9 kgf per kg (35 kgf, 12 kg) | 67 4 kgf per kg (40 kgf, 10 kg) |
Specifications
| Vetus BOW3512E Bow Thruster 35 kgf | Sleipner SE40 Tunnel Thruster 12V | |
|---|---|---|
| Thrust | ||
| Rated thrust | 35 kgf | 40 kgf |
| Thrust at full supply voltage | - | 48 kgf |
| Style | Tunnel | Tunnel |
| Propellers | Single | Single |
| Bow or stern use | Yes | Yes |
| Boat length | 20-30 ft | 26-34 ft |
| Electrical | ||
| Supply | 12 V | 12 V |
| Motor | 1.5 kW | 2.2 kW |
| Current draw | 220 A | 315 A |
| Continuous run | 4 min | 3 min |
| Build | ||
| Tunnel diameter | 150 mm | 125 mm |
| Weight | 12 kg (26 lb) | 10 kg (22.1 lb) |