For a 43 to 62 ft boat with a big battery bank. Most boats this size are better served by a 24 V version if the maker offers one.
Amazon $4,013.39The Sleipner SE130 Tunnel Thruster 12V rates 3.9 among over 75 kgf bow thrusters; the Lewmar 185TT 4.0 kW Gen 2 Thruster rates 3.0 among 45 to 75 kgf ones. The Lewmar 185TT 4.0 kW Gen 2 Thruster costs $913.40 less ($3,099.99 vs $4,013.39).
Prices were last checked November 4, 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.

The strongest 12 V Lewmar in this list. It costs about $48 per kgf; a Vetus BOW7512D gives more thrust for about $1,000 less.
Amazon $3,099.99Scores side by side
These two sit in different thrust classes (over 75 kgf and 45 to 75 kgf), and each is scored against the reference points for its own class, so a rating says how well each does among its own thrust peers. How we rank explains each factor.
| Factor weight | Sleipner SE130 Tunnel Thruster 12V | Lewmar 185TT 4.0 kW Gen 2 Thruster |
|---|---|---|
| Overall rating | 3.9/5 | 3.0/5 |
| Value 40% | 86 $30.87 per kgf ($4,013.39, 130 kgf) | 56 $47.69 per kgf ($3,099.99, 65 kgf) |
| Efficiency 25% | 86 20 kgf per kW (130 kgf, 6.5 kW) | 32 16.2 kgf per kW (65 kgf, 4 kW) |
| Run time 25% | 33 3 minutes continuous | 33 3 minutes continuous |
| Weight 10% | 50 3.5 kgf per kg (130 kgf, 37 kg) | 42 3.2 kgf per kg (65 kgf, 20 kg) |
Specifications
| Sleipner SE130 Tunnel Thruster 12V | Lewmar 185TT 4.0 kW Gen 2 Thruster | |
|---|---|---|
| Thrust | ||
| Rated thrust | 130 kgf | 65 kgf |
| Thrust at full supply voltage | 160 kgf | - |
| Style | Tunnel | Tunnel |
| Propellers | Twin | Single |
| Bow or stern use | Yes | - |
| Boat length | 43-62 ft | - |
| Electrical | ||
| Supply | 12 V | 12 V |
| Motor | 6.5 kW | 4 kW |
| Current draw | 800 A | - |
| Continuous run | 3 min | 3 min |
| Build | ||
| Tunnel diameter | 250 mm | 185 mm |
| Weight | 37 kg (81.6 lb) | 20 kg (43 lb) |