coolant

A Keel Cooler Retrofit

July 23, 2012

Usually associated with long distance passagemaking, keel cooling remains a viable alternative for reliable diesel engine operation. Rather than pumping raw water into your boat

Cavitation erosion (and the related erosion or impingement corrosion) is an infrequently discussed yet frequently misunderstood phenomenon that can lead to metal damage and failure. It can afflict everything from engines and generators to plumbing systems and propellers. Cavitation is the formation of voids or bubbles in a liquid that are a result of forces that act upon the liquid. Its important, however, to distinguish these voids from common bubbles as the latter contain a gas, often air, while the former contain nothing. That is, they are vacuum bubbles. Interestingly, the formation of the cavitation void is tantamount to boiling because the boiling point of a liquid drops as the pressure drops. (Its why mountaineers use pressure cookers; at a high altitude and therefore lower atmospheric pressure, water boils at a temperature lower than 212°F.) Thus, cavitation bubbles are essentially a result of low temperature boiling induced by low pressure. Cavitation may occur as liquid moves swiftly around constrictions and through orifices, particularly when such orifices change shape from small to large, as in water moving past a gate valve, or worse, through a partially opened valve. These conditions create a Venturi effect and the rapid change in pressure is conducive to the formation of cavitation bubbles.

A close-up of a boat's helm at night, showing glowing green and blue electronic navigation screens and radar displays, with blurry city lights visible through the window in the background.

Pro Boat Handling: Timing the Tide

When you can’t go any faster or slower, there are other options to help you arrive safely.

A wide, eye-level shot of a small, white wooden fishing boat named "DAMIEN I NICE" cruising through a calm harbor, leaving a gentle wake in the foreground. A single fisherman sits at the stern near the outboard tiller. In the background, a bustling marina is packed with dozens of docked sailboats and white vendor tents along the waterfront, bordered by a dense hillside of European-style apartment buildings under a clear blue sky.

Dash of Salt: Now We’re Talking

Let’s bring back these nautical words and terms. They’re better than the way we communicate today.

A side three-quarter view of a large, rugged expedition trawler named "PAUL JOHANSEN" cruising through calm open water. The vessel features a dark blue hull creating a white wake at the bow, paired with a cream-colored superstructure and a high pilothouse. A tall central mast holds multiple radar domes and communication antennas, while the upper deck carries a white tender and a bright yellow kayak. An American flag flies from the stern under a grey, overcast sky.

Straight Life

Once a rescue craft, this Norway-built steel trawler is the ticket to ride for a venturesome crew.

When Minutes Matter

Island time is great, except in an emergency. This medevac service is for boaters who need help fast.

A high-angle, eye-level shot looking toward the bow cabin of a large white trawler yacht docked in a marina. A worker in dark blue clothes stands atop the cabin roof structure, using a long-handled brush to scrub the fiberglass surface next to a yellow water hose. The boat features a forward-slanted windshield with multiple wipers, a dark wood-planked foredeck, and stainless steel railings. Other luxury yachts are closely docked on either side under a bright, partly cloudy blue sky.

Stain Masters

Black streaks, yellow mustaches and rust all require different solutions to keep a boat looking clean.

Project Langosta

A Down East icon provides inspiration for this gentlemanly cruiser.

$A wide, eye-level shot capturing a majestic and treacherous Arctic landscape filled with massive white and blue icebergs floating in a calm, dark blue ocean. In the immediate left foreground, a towering wall of sheer ice rises sharply, showing deep fissures and dynamic textures. Behind it, a sweeping, mountainous glacier structure dominates the background under a pale, overcast sky, while a smaller, vibrant turquoise iceberg block sits low in the water on the right, displaying bright, light-refracting edges.$