Choosing the right boat shower pump or sump matters: it keeps your bilge dry, prevents odors, and makes onboard showering reliable. This guide distills extensive research, hands-on testing, and expert feedback to recommend the best pumps and sump kits for a range of boats, budgets, and electrical systems.
How we tested and chose products
What we evaluated
- Real-world performance: flow rate under load, ability to handle graywater (hair/soap), self-priming and anti-airlock behavior, and run-dry tolerance.
- Installation & fit: inlet/outlet sizes, box dimensions, multi-port versatility, and ease of access for maintenance.
- Durability & materials: UV-stable housings, corrosion-resistant shafts/components, and motor cooling strategy.
- Control & protection: float switch behavior, check valves, and anti-clog design.
- Value & availability: price vs. features, replacement parts, and brand support.
Testing approach
- Bench tests to confirm rated flow and current draw.
- Simulated shower sump installation to assess float switch action and auto-shutoff.
- Practical clogging tests with typical shower debris and hair to evaluate anti-choke behavior.
- Comparative noise and vibration checks.
We combined our hands-on findings with user feedback and marine-expert opinions to rank the best models across different needs.
750 GPH Budget Sump
Affordable 12V 750 GPH shower sump offering multiple inlet ports, built-in float switch, and straightforward installation. A smart choice for small boats or RVs that need a no-frills, effective pump at a very low price point.
NovelBee 12V 750 GPH Shower Sump — Best Budget Pick
The NovelBee 12V 750 GPH shower sump is a compact, wallet-friendly option for boaters and RV owners who need reliable water removal without a premium price. It delivers a rated 750 GPH flow, includes multiple inlet ports for flexible plumbing, and uses an internal float switch to automate operation. The intermittent-duty design (30-minute intervals) is typical for small shower sumps and works well when paired with proper plumbing and a strainer.
Key technical details: 12V DC operation, ~3A current draw (as listed), 750 GPH flow, multiple inlet ports for common hose sizes. Installation is straightforward and the multi-port layout fits many retrofit situations. Expect decent performance for the price, though long-term durability will depend on mounting and exposure to heat/salty environments.
Who it's for: budget-conscious boaters, DIY installers, and small-craft owners who need a capable sump pump without spending much.
Whale Gulper 220
A proven premium gray-water pump engineered for reliability: non-clog valves, self-priming to 10 ft, low power draw and the ability to run dry. Ideal for boats that prioritize long-term dependability and low maintenance.
Whale Gulper 220 Pump — Premium Choice
The Whale Gulper 220 is a long-established name in marine gray-water handling. Designed specifically to manage shower waste (including hair and soap), it uses virtually non-choke valves and a design that eliminates filters that require regular cleaning. The pump is self-priming to about 10 feet, offers a 3.5 GPM (≈210 GPH) flow rate appropriate for single-head systems, and will run dry without damage — a valuable safety feature when occasional dry-run events occur.
Technical highlights: 12V DC operation, 3/4" hose connections, double-outlet valve for continuous flow, multi-directional head for tight installations, and low power draw. Its build quality and non-clog performance justify the higher price compared with basic sump kits.
Who it's for: cruisers and liveaboards who need a robust, low-maintenance gray-water pump and are willing to pay for longevity and proven anti-clog performance.
Shower Sump Kit
All-in-one shower sump kit with 750 GPH pump, marine-grade ABS drain box, clear access lid and multiple inlet sizes. Excellent balance of thoughtful design and price — strong choice for most cruisers and owners installing a proper sump system.
SAILINGFLO 12V 750 GPH Shower Sump Kit — Best Value for Money
This kit provides a complete shower sump solution: a 750 GPH automatic pump with an integrated float switch and a sturdy, UV-stabilized ABS drain box with a clear snap-on cover and gasket. Multiple inlet sizes and a removable mesh strainer make it versatile and easy to maintain. The motor cooling and moisture-tight seals improve service life compared with cheaper alternatives.
Technical highlights: automatic float-activated 750 GPH pump, 3/4" outlet with check valve, inlets covering common hose diameters, rugged ABS construction, and user-friendly access for cleaning. The kit’s components are optimized for marine applications, so you get better longevity and cleaner operation for a modest price premium over bare pumps.
Who it's for: boat owners who want a turnkey sump solution with quality materials and easy maintenance without moving into premium pricing.
800 GPH Drain Pump
High-flow 12V drainage pump that fits common shower drain boxes. A reliable, easy-replace option for boats that require stronger flow and parts compatibility with legacy drain systems.
Rule 800 GPH Legacy Shower Drain Pump — Editor's Choice
The Rule 800 GPH Legacy pump is a straightforward, high-capacity 12V option suited for installations where higher flow and compatibility with existing drain boxes matter. With an 800 GPH capability it moves water quickly and pairs well with larger-capacity showers or installations where faster clearing reduces the chance of backflow. The model is designed to fit legacy drain boxes (97A & 98A), making it ideal for retrofits.
Technical details: 12V DC operation and 800 GPH rated flow. Rule's long marine history means easy access to replacement parts and knowledgeable dealer support — a major plus for long-term ownership. While it’s not a fully integrated sump kit with a housing and strainer, its flow and brand support make it a practical top pick for many installations.
Who it's for: owners replacing legacy pumps, those who need higher flow, or anyone prioritizing brand reliability and serviceability for routine maintenance or retrofit projects.
Comparative overview
Key differences at a glance:
- NovelBee 12V 750 GPH (Best Budget Pick) — Lowest price, multiple inlets, decent 750 GPH performance for small boats and DIY installs.
- Whale Gulper 220 (Premium Choice) — Proven anti-clog design, runs dry safely, best for long-term reliability managing gray waste.
- SAILINGFLO 12V 750 GPH Kit (Best Value) — Complete sump kit with marine-grade box, strainer, and reliable motor cooling — best combination of features and cost.
- Rule 800 GPH (Editors Choice) — Higher flow for faster clearing, good for retrofits and users who want widespread parts/support.
Best overall: SAILINGFLO 12V 750 GPH kit stands out as the most balanced option — it combines a capable pump, a purpose-built marine drain box, convenient maintenance features, and a reasonable price. For pure reliability on gray-water challenges, the Whale Gulper remains the top premium choice. For tight budgets, NovelBee gives functional performance at minimal cost. If you need more flow or are replacing an older unit, Rule’s 800 GPH pump is the practical pick.
Final recommendation
After hands-on testing and cross-referencing expert and user feedback, our top recommendation for most boat owners is the SAILINGFLO 12V 750 GPH shower sump kit — it delivers the best blend of durability, installation convenience, and value. If you prioritize long-term, low-maintenance gray-water handling and are willing to pay for proven engineering, choose the Whale Gulper 220. For budget installs or temporary solutions the NovelBee 12V 750 GPH is a pragmatic choice. Finally, if you require higher flow or need a drop-in replacement for legacy boxes, the Rule 800 GPH pump is the editors’ favorite.
Choosing the right unit depends on your boat’s electrical system (12V vs 24V), available space, plumbing diameters, and whether you want a full sump kit or just a replacement pump. These recommendations are based on detailed bench and field testing, technical specifications, and real-user reliability data — so you can pick a solution matched to your needs with confidence.