T-H Marine ATLAS 4" Set Back Hydraulic Jack Plate Polished

The T-H Marine ATLAS 4-inch set back hydraulic jack plate (part AHJC-4V-DP) is the standard-finish 4-inch set back variant of the ATLAS hydraulic jack plate - the most-installed hydraulic jack plate on factory-built bass and walleye boats from major boat manufacturers. Polished aluminum finish (the STD variant - the alternative is the BLK black-anodized finish at the same price). Rated for outboard engines up to 300 horsepower or 625 pounds dry weight. The right hydraulic jack plate for boats running outboards in that weight / horsepower class where you want hydraulic engine height adjustment for optimal performance across different running conditions.

Why a hydraulic jack plate. Outboard engine height (the vertical position of the engine relative to the boat's hull bottom) significantly affects boat performance: too low and the engine creates excessive drag (slower top speed, lower fuel economy), too high and the prop ventilates and loses thrust (slower acceleration, prop slip). The ideal height varies with boat speed, load, water condition, and even the specific prop you're running. A hydraulic jack plate lets you adjust engine height on the fly via a rocker switch at the helm: raise the engine for top-speed runs in calm water, lower for hole-shot acceleration with full load, fine-tune height for specific water depth (shallow flats fishing in skinny water needs the engine raised). The result is meaningfully better performance across the boat's full operating envelope vs. a fixed-height transom mount.

4-inch set back. The 4-inch set back means the engine mounts 4 inches further back from the boat's transom than it would on a flush transom mount. The set back gives the propeller cleaner water flow (away from the boat's wake disturbance) for better thrust and efficiency, plus provides clearance for the engine to lift up during jack plate operation. 4-inch is the standard set back for typical bass and walleye boat applications. For shallow-water boats wanting more set back (5-inch, 6-inch, etc.), T-H Marine makes other ATLAS variants in those set back ranges.

Up to 300 HP or 625 lb engine. The 4V variant of the ATLAS line is rated for outboards up to 300 horsepower or 625 pounds dry weight, whichever comes first. Modern 250 HP and 300 HP outboards typically weigh 500-625 lb, so the 4V handles the typical 250-300 HP outboard class. For larger outboards (350 HP and up, typically 700+ lb), step up to the higher-capacity ATLAS variants (the 6V or 8V). For smaller outboards (under 250 HP), the 4V is overkill and a smaller ATLAS variant saves weight and money.

Integrated actuator design. The hydraulic actuator that lifts and lowers the engine is built INTO the jack plate body, not as a separate external component. T-H Marine / CMC was the first manufacturer to integrate the actuator inside the jack plate (the competition copied later). The integration matters for several reasons: cleaner appearance (no external hydraulic lines visible), lower failure surface area (no external lines to chafe or fail), simpler install (no external plumbing to route), and better protection of the actuator from impact damage and saltwater spray.

No grease lubrication required. The ATLAS is engineered without the typical grease-zerk lubrication points that older jack plates required (and that most competitors' designs still require). The internal slide mechanism uses sealed bearings and self-lubricating components that don't need periodic grease service. For boat owners, that's one less maintenance task to remember and one less failure mode (lubrication missed = stuck slide). For dealers and service shops, it means easier service and fewer warranty claims from missed lubrication intervals.

Predrilled for shallow water anchors. The ATLAS body comes predrilled with the standard shallow-water-anchor mounting hole pattern, so installing a Power-Pole, Talon, or other shallow-water anchor on the boat is plug-and-play with the jack plate already accommodating the mount. Other jack plates require drilling into the boat's transom around the jack plate or modifying the jack plate itself to accommodate the anchor. The ATLAS predrills make the integrated install much cleaner.

Heavy-duty safety cable. The integrated safety cable connects the engine to the boat's transom independently of the jack plate's mechanical structure. In the unlikely event of a complete jack plate failure (mechanical structural failure that wouldn't normally occur in any reasonable use), the safety cable prevents the engine from falling backward into the cockpit and injuring crew. T-H Marine was the first jack plate manufacturer to include the safety cable as a standard feature - it's a meaningful belt-and-suspenders safety design.

Field-replaceable actuator. If the hydraulic actuator ever needs replacement (after many years of service), the ATLAS design allows field replacement of just the actuator without removing the entire jack plate from the boat. Replace the actuator in 30-60 minutes of shop time. Other designs that bond the actuator into the jack plate require removing the whole plate from the boat for actuator service - significantly more shop time and more disruption.

US-made hydraulic actuator. The ATLAS hydraulic actuator is manufactured in the United States. Most competing hydraulic jack plates use Chinese-made actuators that have a less consistent quality history. The US-made actuator is part of why ATLAS jack plates have the long-term reliability reputation that has made them the most-installed factory option on major-brand bass and walleye boats.

Polished aluminum finish (STD). This variant has the polished aluminum standard (STD) finish - the bright shiny aluminum look that matches typical bass-boat polished aluminum trim. For boats with black-themed hardware (more common on modern boats with blacked-out hardware), the BLK black-anodized finish is the alternative variant at the same price. Functionally identical jack plates - just choose the finish that matches your boat's hardware aesthetic.

Install. The ATLAS bolts to the boat's transom in the four standard outboard mounting holes (typical install pattern - matches the engine's mounting holes on the boat-side, then the engine bolts to the jack plate's mounting plate using the engine's standard mounting pattern). Wire the hydraulic actuator's electrical leads to a momentary helm switch with appropriate fuse on the 12V boat electrical system. Total install time is typically 4-8 hours for a fresh install, less for a like-for-like jack plate replacement. Should be installed by someone with experience working on outboard engine mounts.

What's in the box. The ATLAS 4-inch set back jack plate (with integrated actuator), mounting hardware, hydraulic actuator wiring harness, helm switch, install instructions. Required separately: 12V power wiring with appropriate fuse for the helm switch.

T-H Marine warranty applies. Same-day shipping before 3 PM ET on in-stock units. Note: this is an oversize 51 lb shipment that may incur freight surcharges from carriers on certain routes.