Spotlight: Mercury 350 SeaPro

The 350hp Mercury 350 SeaPro uses the same V10 block as the 350hp and 400hp Mercury V10 Verado engines, but with tweaks to its performance and engineering to build longevity into the system. It can also come with Mercury’s optional electro-hydraulic or space-saving fully electrical steering system.

This includes limiting the operating rev range to between 5300rpm and 5900rpm, cowling seals that keep out moisture and suppress noise, and a boat-mounted water-separating fuel filter kit.

The Mercury 350 SeaPro uses the same lower leg as the V10 that features a larger torpedo that helps with lift and helps to swing the largest propeller of any single-prop system on the water. The gearcase oil can be drained via the torpedo to make it easier to service.

This oversized propeller helps the big V10 outboard engine grip the water and take advantage of the torque generated by the big-displacement powerhead.

The big SeaPro also gains from Mercury’s 150A alternator output, although nothing is mentioned about the option of fitting the engine with a switchable 12/48V alternator that’s available on the recreational-focussed versions.

Regular maintenance on the engine is simplified, with a lid built into the top of the cowling giving access to the colour-coded touchpoints that should be regularly checked.

Users who fit multiple engines to their workboat can equip the engines with Mercury’s Joystick Piloting for Outboards system that allows the vessel to be controlled with small, precise movements or even automatically held at station.

Mercury claims the 350 SeaPro operates at up to 28 per cent more quietly at cruising speeds compared with one of its rivals, reducing the chance of fatigue on the operator.

The Mercury 350 SeaPro also uses Mercury’s ‘Advanced Midsection’, an engine mount that helps to stop engine noise and vibration from being transferred to the hull. It also helps to dampen the torque produced by the big prop.

The V10 Mercury 350 SeaPro sits below the 7.2-litre V12-engined 500 SeaPro and above the 4.6-litre V8-engined 300 SeaPro in the commercial outboard engine line-up.