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Podded electric drives put the propulsion motor inside a steerable underwater gondola and now power more than 100 cruise ships and 80 ice-going vessels, led by ABB's Azipod. In September 2026 Kongsberg Maritime extended its Elegance pods to 22 MW, the first credible challenge to ABB in the mega-cruise class in over a decade.
Mechanical azimuth thrusters transmit engine or motor power through right-angle gears to a steerable propeller, giving tugs, offshore and DP vessels 360-degree thrust vectoring. The market is small, roughly USD 0.5 to 0.6 billion a year by aggregator estimates, so growth comes from permanent-magnet, hybrid and underwater-mountable designs rather than volume.
A fixed-pitch propeller is cheaper and 2 to 5 percent more efficient at its design point, while a controllable-pitch propeller keeps the engine at constant speed and delivers better astern thrust. In 2025-2026 the CPP has become the spine of hybrid cargo ships and the object of consolidation, with Kongsberg Maritime acquiring Berg Propulsion.
A contra-rotating propeller pairs a coaxial aft propeller turning opposite to the forward one, recovering rotational energy for vendor and model-test gains of roughly 7.6 to more than 10 percent. Hurtigruten's Sea Zero zero-emission ship and SINTEF's 2025 testing of Brunvoll's CRP have revived a concept long held back by shaft-in-shaft complexity.
A waterjet draws water through a hull inlet and ejects it through a steerable nozzle, beating propellers only above roughly 25 knots but winning on draught, stopping power and noise. In 2026 Kongsberg launched the 33 MW Kamewa S-4L and booked its largest ever waterjet order, while HamiltonJet, MJP and Thrustmaster electrify and expand the small-jet market.
Cycloidal propulsion uses a rotating disc of vertical blades to deliver thrust in any direction almost instantly, which is why Voith Schneider Propellers dominate escort tugs and double-ended ferries. Voith marked 100 years of the design in July 2026, while ABB's Dynafin concept claims up to 22% better efficiency but had no commercial order by late 2025.
A Kort nozzle accelerates flow through the propeller and can lift bollard pull by up to 30%, which makes ducted propellers standard on tugs, trawlers and icebreakers. The duct's drag erodes the gain above roughly 10-12 knots, so current nozzle development targets transit fuel economy with vendor claims of 3.5-10%.
Propulsion energy-saving devices are hull appendages such as pre-swirl ducts, stators, boss-cap fins and transom foils that recover losses around the propeller. Independently measured gains run 3-10% per device, and EEXI and CII rules let owners credit them, yet Lloyd's Register found fewer than 2% of the world fleet carries one.
Rim-driven thrusters carry the propeller blades on a rotating ring driven by a permanent-magnet motor in the duct, so there is no gearbox, shaft or blade tip. Their decisive selling point is low underwater noise, which won Kongsberg a DNV Silent-E notation in 2024, while suppliers now scale units toward 1.6-3.5 MW.
Dynamic positioning holds a vessel's position and heading with computer-controlled thrusters, and offshore wind has turned a near-standard DP2 package of azimuth, retractable and tunnel thrusters into a volume product. Spinergie counted 85 active SOVs in August 2025 with 48 more due, while cruise ships are pushing tunnel thrusters to 4,000 kW.
Two-stroke low-speed marine engines are direct-coupled crosshead diesels that still power nearly all deep-sea cargo ships, with the largest unit rated 75,570 kW. Three designers, Everllence, WinGD and J-ENG, now sell LNG, methanol and ammonia variants, and the first ammonia-fuelled two-stroke ships entered service in 2026.
Four-stroke marine engines drive cruise ships, ferries, offshore vessels, tugs and the generator sets of every large ship, with the Wartsila 31 holding a Guinness record at 169.4 g/kWh. Between 2024 and 2026 Wartsila, Everllence, Rolls-Royce mtu, Caterpillar MaK and HD Hyundai HiMSEN all added methanol or ammonia versions of their base platforms.
Marine gas turbine propulsion uses aeroderivative turbines such as the 25,100 kW GE LM2500 and the Rolls-Royce MT30 for warships and fast craft where power density matters more than fuel cost. Naval frigate and destroyer orders in 2025-2026 drive the market, while a 16 MW ammonia turbine targets a full test by end-2027.
Marine steam turbine propulsion was the standard LNG carrier prime mover because boilers burn boil-off gas simply, but at about 30% thermal efficiency it trails DFDE plants above 42% and two-stroke gas engines by more. Record scrapping in 2025 and widening lay-ups in 2026 leave nuclear as the only growth route for marine steam.
Marine waste heat recovery turns exhaust and cooling-water heat into electricity or shaft power, with full steam-cycle systems recovering about 5% of fuel energy and Siemens reporting fuel savings of up to 12% on container ships. Since 2024 the growth has shifted to modular organic Rankine cycle units and hybrid turbochargers that work at low load and suit retrofits.
Diesel-electric and integrated electric propulsion feed propulsion motors, thrusters and hotel loads from one electrical bus, while DC grids let gensets run at variable speed and connect batteries directly. ABB, Siemens Energy and GE Vernova lead the segment, which now underpins hybrid ferries, offshore vessels, naval combatants and the first cruise-ship DC retrofit.
Hybrid marine propulsion pairs engines with a battery for peak shaving, spinning reserve, engine-off port operation and regeneration, and hybrids make up 68% of the Maritime Battery Forum register. Documented savings range from 4-5% on steady transit to 20-30% on tugs and DP vessels, so the value depends on load profile.
Battery-electric ships carry lithium-ion packs charged from shore and drive motors, pods or waterjets, and the Maritime Battery Forum register passed 2,000 vessels with about 2.4 GWh in October 2026. The 130 m China Zorrilla entered service with more than 40 MWh, while charging power has scaled from 1 MW to planned 55 MW.
Hydrogen reaches a propeller through PEM or solid-oxide fuel cells feeding electric drives, or through hydrogen combustion engines, and modules from Ballard, PowerCell, Yanmar and Hanwha now hold class approvals. Only about seven hydrogen-fuelled ships are in operation, and MF Hydra's trucked liquid hydrogen at EUR 13-14 per kg shows why.
A shaft generator lets the main engine supply hotel load in PTO mode and, as a permanent-magnet machine, motor the shaft from gensets or batteries in PTI mode. Wartsila puts the EEXI gain at 3-5%, and ABB booked 30 LNG carriers in one order, while superconducting motors remain in naval research.