Pitot Tubes & Accessories
What Are Marine Pitot Tubes?
Marine pitot tubes and accessories are essential components of a boat's speedometer system. A marine pitot tube is a device used to measure the speed of a boat through the water. It operates on the principle of fluid dynamics — specifically Bernoulli's principle — which relates the pressure of a fluid to its speed. As the boat moves forward, water enters the tube's front-facing opening, creating pressure that is transmitted through tubing to the speedometer, which then converts that pressure into a speed reading in mph or knots.
Unlike a car speedometer that tracks wheel revolutions, a boat has no rotating wheels to measure movement. The pitot tube solves this elegantly: as the boat accelerates, water pressure inside the tube increases proportionally, giving the gauge a real-time, reliable speed reading. The concept was first engineered by French inventor Henri Pitot in the early 18th century, and it remains a trusted, cost-effective method for measuring speed through the water on recreational boats today.
What's Included in This Category?
Pitot tubes and accessories encompass everything needed to install, replace, or maintain a boat's pressure-based speedometer system. This includes:
- Replacement pitot tubes — the transom-mounted probes that interface directly with the water
- Pitot tube kits — complete sets including PVC tubing, clam shell vents, tube holders, and mounting hardware
- Bulk pitot tubing — for custom-length runs between the transom probe and the speedometer gauge
- Tube couplings and fittings — brass and plastic connectors for secure, leak-free joins
Why Pitot Tube Condition Matters
A damaged or clogged pitot tube is one of the most common reasons a boat speedometer fails to read accurately. Weeds, debris, or a small crack in the tubing can disrupt water flow and cause erratic or dead gauge readings. Regularly inspecting the tube and connected hose for holes, cuts, or blockages is a key part of seasonal boat maintenance. When winterizing, it's also important to blow trapped water out of the system to prevent freeze damage to the internal components of the speedometer.
When shopping for a replacement, confirm that the pitot tube is compatible with your speedometer's pressure range — most recreational boat speedometers operate in the 30–80 mph range. Also consider tubing length to ensure a proper run from the transom to your dash, and look for protective features like a kick-up design that allows the tube to deflect on impact rather than snap.
Top Brands in Marine Pitot Tubes & Accessories
Seachoice is one of the most recognized names in marine accessories and offers a strong lineup of pitot tubes and kits. Their replacement pitot tubes feature a weed-resistant system that provides steady water pressure for accurate readings, along with a kick-up feature that helps prevent breakage — making them a go-to choice for boaters looking for an affordable, universal replacement.
Sierra is a long-established marine parts supplier whose pitot tubes are engineered to meet or exceed original equipment specifications. Sierra's universal pitot tubes feature a slotted mounting plate design that allows replacement of most competitive brands without drilling new holes, and they are rated for use with any pressure-driven speedometer up to 80 mph.
Brass Fittings rounds out the category with pitot tube couplings and connectors — the small but critical hardware pieces that keep the pressure system sealed and leak-free between the transom probe and the speedometer gauge.