The hull design typically used with each individual drive also plays a role. Both sterndrive and Forward Drive boats commonly feature a deeper vee, resulting in a steeper banking characteristic in aggressive turns at speed. Most V-Drive hulls, in contrast, feature less deadrise and typically turn flatter.
The true separation between sterndrive-based and V-Drive systems is found in reverse. Even at slower speeds, the vectored thrust produced by sterndrive and Forward Drive provide relatively predictable, nimble handling in any direction, a clear advantage whether backing off the trailer, away from the dock or navigating tight confines.
As a V-Drive has minimal water flow passing across the rudder at low speeds, control in reverse is mostly influenced by prop rotation and torque, the directional force created by the propeller.
The typical V-Drive will pull well in one direction when in reverse but have little directional pull in the other. Given this characteristic, many V-Drive manufacturers have begun to add optional thrusters or pivoting fins just forward of the propeller to improve backing performance.
As to performance, expect comparably-powered boats equipped with each drive system to excel in some aspects and perform less strongly in others. Pure top speed favors the sterndrive and Forward Drive. A V-Drive simply has far more hull in the water and runs at a lower angle. Acceleration, however, favors the V-Drive. Due to the downward angle of the driveshaft, V-drives direct thrust not just aft but at a negative angle, allowing them to quickly leverage the hull onto plane.
By comparison, sterndrive and Forward Drive, even in the fully submersed position, direct their thrust almost straight back, causing the bow to raise higher as the boat climbs out of the water before planing atop the surface.
Sterndrives and Forward Drives also have to overcome the weight and bulk of the drives themselves, located far aft on the transom. The shallower deadrise of most V-Drive-equipped hulls also play a role. As to fuel economy, drive systems are similar at slow speeds, but sterndrive and Forward Drive both typically prove superior to V-Drive at higher speeds.
Again, trim plays a role, with the trimmable drives able to dramatically reduce their wetted surface. Jet boats are fastest off the starting line but they generally lack on fuel efficiency and top speed.
Both sterndrive and Forward Drive units can be trimmed, or even raised partially out of the water. Many consumers think an inboard is a sterndrive simply because it is NOT an outboard.
This is not the case as an inboard in the design where the propshaft protrudes thru the boat hull whereas an IO has the engine in the boat and the outdrive mounted on the outside of the boat. Straight Shaft Inboard These are normally associated with the older boats where one engine turns left hand an dthe other right hand. The difference is that the propshaft runs ahead, rather than rearward, at the bottom of the drive unit. This enables dual propellers to be mounted at the front of the driveway, tucking props safely under the hull and allowing Forward Drive to be a feasible choice for the fast-growing wakesurf marketplace.
Conventional sterndrives, with the prop located well aft of the transom, aren't safe to use for its sport due to the rider's close proximity to the propeller. The motor is positioned degrees from its typical orientation so that the driveshaft runs ahead. This driveshaft then connects with a gearbox positioned beneath the cockpit floor, and power redirected back toward the stern and at a downward angle by means of a propshaft that exits through the hull and comes with a fixed-position propeller well forward of the boat's transom.
Jet drives or jet-powered boats mate the inboard motor to a jet pump which draws in water from the consumption at the base of the hull and expels a high-powered water flow from the nozzle on the stern of the ship to propel it forwards. As there is no propeller to strike the earth, they can get into shallower water and are also safer for watersports and swimmers as there is no dangerous moving propeller behind the boat.
As you might expect, the physics behind each push system -- and the consequent influence on handling -- is notably different.
As both sterndrive and Forward Drive place propeller and rudder on the exact same movable drive unit, they pivot in unison based on the driver's activities in the steering wheel. The result is known as"vectored thrust," as the propeller's thrust is able to be directed from the way the captain wants the ship to go.
A V-drive's propeller, by comparison, is locked in a fix position and thrust directed straight back. A separate movable rudder, located in that prop's slipstream, is what affects the ship's direction, again based on the driver's input in the steering wheel. While both create remarkable handling results when going forward, the V-Drive typically proves more agile as the rudder, freed from the bulk of a sterndrive's housing, may pivot throughout a significantly greater range as much as degrees.
In contrast, stern and Forward Drive components typically swing through roughly a degree arc. Most V-Drives also contain additional tracking fins under the hull, forward of the propeller.
The placement of each drive also changes the hull's pivot point, with the V-drive's pivot point a lot more focused beneath the hull, a Forward Drive's more aft, and also the sterndrive the furthest aft of those three.
Jet drive ships can be harder to steer than the other drive systems recorded here and also the aftermath they create is often more tumultuous. Additionally, waterborne debris can get sucked into jet pushes more easily, which may lead to vibrations and issues using propulsion, steering and handling.
Furthermore sterndrives have a tendency to handle rough water better than jet boats and can be trimmed to adjust to water requirements, whereas jet drives can't. The hull design usually utilized with each individual drive also plays a role. The two sterndrive and Forward Drive ships commonly feature a deeper vee, resulting in a steeper banking characteristic in aggressive turns at speed. As a trade off, shaft drives are less efficient and sterndrives provide more fuel efficiency and higher top speeds when installed in planing hulls.
As a general rule of thumb, sterndrives that are moored in salt-water are the most expensive propulsion type to maintain when compared to shaft drives and outboards. This is due to the additional moving parts, limited access and regular cleaning and maintenance required. Shaft-drives So, what about shaft-drives? But what does it cost to swap one of these transom assemblies out?
Is shaft drive better than sterndrive? Are sterndrives expensive to maintain? Explore More. The 3 Different Types Of Boat Maintenance What are the difference types of maintenance that can be applied to engines and equipment on boats?
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