Number of hours you can expect a gas marine engine to typically last before needing major overhauls. A diesel lasts about 5,000 hours. No hourly figures exist for outboards, but 10 to 15 years in salt water is common.
It Never Stops
To calculate how much it will cost to keep a boat going, figure to pay from 2 percent to 5 percent of the original cost (new) per year in maintenance.
Sound of Silence
The most effective sound insulation is layers of foam core to reduce low-frequency sounds, thin sheets of lead to cut down on higher-frequency noises and Mylar or aluminum foil sheathing to protect the insulation from heat. Look for a minimum combined thickness of one inch.
Many engine compartments, and the engines in them, are starved for fresh air. increasing a 3-inch round vent to 4 inches almost doubles its volume.
For every foot of draft in fresh water, your boat will rise almost one-quarter inch when immersed in salt water. A boat drawing three feet on Lake Huron will draw only 2 feet 11¼ inches in the Atlantic Ocean.
Quick and Dirty Method
For small, lightweight runabouts of 24 feet and less, use the 1:25 rule. For every 25 pounds of weight (including engine, gear, fuel and crew) you’ll need approximately one horsepower to get on plane and cruise at a reasonable speed.
Hanging by a Thread
The length of a bolt is correct for the job if at least two threads are exposed past the nut after tightening — the first couple of threads do not have full strength.