In an era when cruising boats bristle with high-tech electronics — from chart plotters with AIS overlays to radar that paints a perfect picture of the anchorage — it’s easy to overlook simpler tools that deliver outsized value. One such device is the humble handheld laser rangefinder, originally designed for golfers and hunters, but now earning its keep aboard many blue water yachts. At around the size of a small pair of binoculars and often costing less than a good dinner ashore, a laser rangefinder provides instant, accurate distance measurements that can transform how you anchor, navigate tight passages, and maintain situational awareness. We have used a laser rangefinder aboard Avant for over ten years, and it has more than earned its keep.
Why Cruisers Reach for a Laser
Most experienced sailors know human depth perception on the water is notoriously unreliable. What looks like 200 feet to the beach often turns out to be 400, or vice versa. This optical illusion has led to countless dragged anchors, near-misses in crowded bays, and heated VHF exchanges with neighbors who are convinced that you’re encroaching on their swing circle.
A laser rangefinder eliminates the guesswork. Aim the device at a shoreline, rock, or another boat, press the button, and in a fraction of a second you have a reading accurate to within a meter or two, out to 500–2,000 yards (depending on the model and conditions). While radar will give range, it takes time to boot up and is less intuitive than a laser rangefinder, especially when your boat (and all the others in the anchorage) are doing the Watusi in a middle-of-the-night squall.
Real-world applications abound:
- Anchoring with Confidence — Measure exact distance to shore or obstructions to deploy the precise scope you need. In a crowded anchorage, check distances to surrounding boats and calculate your swing radius if the wind clocks 180°.
- Predicting Swing Circles — With 5:1 scope in 10 meters of water, your stern is about 45 meters from the anchor. A quick laser shot to the shallows abeam or behind you answers the question: “If the wind shifts tonight, will we still be in deep water?”
- Stern-Tying and Med-Mooring — In British Columbia, the Greek Islands, or Patagonia, knowing the exact distance to a tree, rock, or quay removes the trial-and-error (and extra dinghy rowing) from laying a shore line.
- Wildlife Regulations — In places like BC or Mexico, minimum approach distances to whales, dolphins, or sea lions are strictly enforced. A rangefinder ensures you’re legal — and respectful — without creeping too close.
- Narrow Passes and Uncharted Reefs — Where charts are outdated or nonexistent, a rangefinder supplements radar and visual piloting. In fog or at night (with an illuminated model), it gives hard numbers when eyeballing just won’t do.
Choosing the Right Model
Not all rangefinders are created equal for use on a wet, salty boat. Look for:
- Waterproof or highly water-resistant construction (many hunting models are fully sealed).
- Nominal range of at least 800–1,000 yards to reflective targets (boat hulls and rocks work well; water surfaces and trees less so).
- An illuminated LED or OLED internal display makes it easier to use in low light or night-time conditions. A plain LCD can be very difficult to read in these conditions.
- On some hunting models you pay a premium for a complex ‘ballistic model’ for calculating bullet drop. For use aboard, you can eschew this functionality.
- Recognize that the real-world useful range is almost always less than the manufacturer’s nominal spec, especially in gnarly conditions aboard: rain, spray, high humidity, or any hint of fog can scatter the laser beam and dramatically shorten effective distance. Expect performance to drop off sharply in poor weather and consider ‘buying up’ to a longer-range model to compensate.
Small Investment, Big Payoff
A laser rangefinder won’t replace your binoculars, radar, or depth sounder, but for the weight of a paperback book and the cost of a fancy new winch handle, it adds a layer of precision that can help you make better decisions.
Next time you’re updating the nav station toy box, consider adding this pocket-sized powerhouse. You’ll wonder how you ever cruised without it.