After spending a few weeks in the Netherlands, I found myself marveling at a process I’d once considered purely functional: boating through locks. In a country where entire cities are below sea level, locks are vital for controlling water and preventing floods. It’s quite different from the United States, where locks are primarily used to manage water levels in manmade canals.
Lock structures allow boats to traverse sections of water at differing heights. It’s a process that may seem daunting at first, but that becomes second nature with a little basic understanding and good boat preparation.
Locks are, in essence, water elevators for boats. Picture a chamber with gates at both ends. When a vessel enters, the entrance gate behind the boat closes, and the water level inside the chamber rises or falls to match the water on the other side of the exit gate. Once the water levels are the same on both sides of the exit gate, the doors open and the journey continues.
Though locks come in all sizes, their operation follows the same simple principle. The real difference lies in how water enters or exits the chamber, with each approach potentially affecting the boat differently.
One method of filling or draining water from the chamber is through valves or sluices at the bottom of the chamber. The gradual rise of water makes the process steady and predictable, but it’s not without its demands. Turbulence can occur, especially in larger locks, as swirling currents move the boat around. Constant attention to the boat’s position is required, and lines must be monitored to keep the vessel stationary. Otherwise, the boat can drift or bump against the lock chamber wall or another boat. For beginners, this type of lock is often less intimidating, but vigilance is still essential.
The alternative method of filling or draining a lock is by slightly opening one of the gates, allowing water to rush in or out. This approach can feel more abrupt, as water enters quickly, raising the boat at a faster pace. The resulting turbulence near the gate can be intense, pushing boats against or pulling them away from walls if lines aren’t secure. Positioning becomes critical here, and the lock keeper often controls the flow to minimize the impact.
These types of locks demand precision and readiness. Boats must be held fast against the force of the current. This task is easier when the boat is being lifted in the lock because you’re keeping the line taut while the boat is rising. It is a little more of a challenge when the boat is falling within the chamber, because you have to let the line pay out while simultaneously holding the boat secure. In both cases, you need to be ready for unexpected movements and changing conditions.
Approaching the lock, you will typically encounter a red-and-green light system. Always call the lock tender on VHF channel 13 to request permission before entering the lock chamber. While speaking on the radio, ask on which side of the lock they want you to tie, and whether you will need your own line or if there are lines hanging on the lock walls for you to use. That way, you can have lines and fenders ready before entering the chamber.
The lock tender will indicate when it is safe to enter by presenting a green light, inviting you forward. Enter slowly and under control. Once the boat is inside the chamber, the lock tender will guide you on where and how to tie up.
Exiting the lock is a reverse of this process. The lock tender will show a green light to vessels inside the chamber once the water levels equalize and the gate opens. At this time, ensure that your lines are released cleanly, and proceed slowly.
Preparation is the key to navigating any lock. Especially in locks that fill by opening a gate, it is important to prepare your boat with plenty of fenders to protect it from the chamber walls. Include a fender farther forward than you my think necessary, as the boat can pivot drastically. Crew should be ready at the bow and stern to prevent last-minute confusion. Communication is important, whether through hand signals, radios or headsets. Patience is perhaps the most underrated tool. Locks are shared spaces, and the process often involves waiting, sometimes longer than anticipated.
For those new to boating, each lock is an opportunity to refine your skills. The more locks you encounter, the more intuitive the process becomes. Over time, you’ll learn to anticipate the movements of your boat, adapting to different conditions with confidence.
Ultimately, locks are more than just functional structures. They are gateways enabling you to explore waterways that would otherwise be inaccessible. With preparation, patience and an understanding of how locks work, navigating becomes not only manageable but rewarding. Like any aspect of boating, the experience increases with time, transforming what once felt like a challenge into an enjoyable part of the journey.
