Mercury 300XL SeaPro Commercial

Built for commercial duty, the new Mercury 300XL SeaPro Commercial is a 300 hp V8 calibrated to build torque at lower rpm so a crew can run it hard, day after day, without overworking the engine. It carries a 25-inch shaft and a gearcase rated at three times the service life of a recreational one.

Why the gearcase is built differently

SeaPro's gearcase was designed with upkeep in mind, including a torpedo housing that lets oil drain out quickly during routine checks, which matters on an engine that may run daily rather than on weekends only. The same 4.6-liter, 279 cid V8 block reaches full throttle at a lower 4800-5600 rpm here than the recreational tune does.

Controls and steering choices

This SeaPro is fitted for remote mechanical controls, with hydraulic, power, or Big Tiller steering offered only as options, so plan on sourcing whichever setup matches your boat separately. At 527 lbs dry, with 32 valves over the V8's twin camshafts, it carries the same weight Mercury quotes across this recreational-tuned 300 hp block.

Is this engine meant for constant use? Yes, SeaPro models are built specifically for heavy, repeated commercial service rather than occasional outings.

Does Big Tiller steering come standard? No, it is one of several optional steering choices for this motor.

Being sold new, it arrives without prior hours and ready to commission once your control and steering choice is confirmed against this SeaPro build.