Mercury 300 HP SeaPro Electric Start, Steering, Power Trim and Tilt, Extra Long Shaft Outboard Motor

The Mercury S 300 XL SeaPro is a 4-stroke outboard marine engine designed for commercial fishing boats, rental tour boats, water taxis, and high-usage vessels requiring an extra-long shaft. It features a 300 HP / 224 kW and 4600 cc V8 (8 Cylinder) engine. The SeaPro series is a Mercury line specifically developed for commercial and heavy-duty outboard motors. Increased durability, SmartCraft integration, and extended service intervals are optimized to meet the needs of commercial operators.

S 300 XL SeaPro Series Features and Technology Advantages

SeaPro engines aim for long life in saltwater environments with a reinforced cooling system and increased anode protection compared to standard FourStroke series. The SmartCraft gauge system enables fleet-specific engine monitoring.

• V8 (8 Cylinder) Engine (4600 cc): SeaPro engines aim for long life in saltwater environments with a reinforced cooling system and increased anode protection compared to standard FourStroke series.
• Extra Long Shaft (572 mm (22.5")): The propeller operates at an optimum depth with the correct transom height.
• SeaPro Durability Package: Reinforced cooling, increased anode protection, and long service intervals.
• Electric Start: Instant activation with key or button — comfortable and quick starting.
• Power Trim & Tilt: Adjust trim angle with a button while cruising — optimizes fuel efficiency; tilt allows raising the engine completely.
• Floating External Fuel System: Connection for a large-capacity external tank — range is determined by user needs.

Extra Long Shaft — Which Boat Type Is It Suitable For?

The extra-long shaft (572 mm (22.5")) ensures the propeller operates at the correct water depth on large fiberglass and aluminum boats with high freeboards. It is 64 mm longer than the standard long shaft (508 mm).

Technical Specifications

Who Is This Engine For?

• Commercial fishing and tour boats: SeaPro's increased durability for intensive daily use.
• Water taxi and rental boats: Low maintenance costs and long service intervals.
• Search and rescue and patrol boats: Reliable power and SmartCraft engine monitoring.
• Coastal fishing fleet-specific: Standard comparative performance and durability.

Maintenance and Longevity

4-stroke Mercury engines operate smoothly for many years with regular oil changes and end-of-season maintenance protocols. The impeller of the water-cooled system should be checked every 100 hours or every two seasons. For saltwater use, freshwater flushing is mandatory after each use.

Related maintenance categories: Maintenance Kit | Engine Oil | Impeller | Mercury Spare Parts

Frequently Asked Questions

Why is the Mercury SeaPro 300 HP recommended for commercial use?

The SeaPro series offers a reinforced cooling system and increased anode protection compared to standard FourStroke engines. SmartCraft integration facilitates fleet management and engine monitoring. Long service intervals reduce operational costs.

What does the SmartCraft system provide in SeaPro engines?

SmartCraft transmits engine status, fuel consumption, temperature, and hourly operating data to a digital display. In multi-engine configurations, each engine can be monitored separately. The early warning system prevents unexpected failures.

What are the maintenance intervals for SeaPro engines?

SeaPro engines are designed for long service intervals. Oil changes should be performed according to manufacturer recommendations. For saltwater use, freshwater flushing after each use and an end-of-season anode check are mandatory.

Which boat and vessel brands are compatible with the S 300 XL SeaPro?

Mercury outboard motors are compatible with many fiberglass, aluminum, and inflatable boat models thanks to their universal transom clamp or transom mounting system. The only criteria are your boat's transom height of 572 mm (22.5") and the maximum engine power approved by the manufacturer. You can get compatibility confirmation from Clever Marin by sharing your boat model.

Related Products and Categories

• Mercury Outboard Motors
• Mercury Marine Products
• Mercury Spare Parts
• Mercury 75–150 HP FourStroke
• Mercury SeaPro Motors
• Outboard Motors
• Boat Engines
• Maintenance Kit
• Impeller
• Anode

Is This the Right Configuration for Your Boat?

Share your boat model, transom height, and intended use — let's verify together if the Mercury S 300 XL SeaPro engine is suitable for your boat and ensure the correct shaft selection.