Sunday Sep 13 2009
Boat not running as fast as you like; it might be the prop
By: George deVilbiss
A boat is a big investment and it doesn’t matter if it’s a small aluminum or something considerably larger. Unless your boat is powered with a jet drive you are relying on a propeller to move that boat regardless whether it is an outboard, inboard or an I-O. When you purchase the boat, there will be a prop attached but the propeller the manufacturer will include will be the “average” prop, one that will give you “average” performance. It may not be the propeller that will optimize the performance for that particular craft. Most boaters want to get up to speed quickly, to get out of the hole and on a plane immediately, and to get from Point-A to Point-B as fast as possible. Many anglers will utilize the same motor for trolling, so alone or with the aid of a trolling plate, the same propeller needs to get down slow enough for effective trolling. If you’re not getting the performance from your boat that you want and expect, it could very well be the propeller, not the power in the motor itself. A bigger prop? Smaller prop? What effect do different props have on your boat? Every prop will have two descriptive figures, such as 14-1/2 x 21. The first number is the diameter of the prop itself and the second number is the pitch. Pitch is the theoretical forward movement of a propeller through a solid medium for one revolution. For example, a 21 pitch prop will theoretically advance 21 inches per revolution. If you want to increase your RPMs, you go down in pitch. On average, for every two inches of pitch, the RPM will change by 400. For water sports and extra people on board, you should drop the pitch by two inches to compensate for the added weight and drag on your boat. Why doesn’t a larger propeller move you faster? Too much diameter can result in performance loss due to the fact that your engine no longer has enough power to efficiently turn the propeller at the recommended RPM operating range. On many boats, you’ll see stainless steel props. They are indeed pricey but are they worth it? To keep costs down, manufacturers mainly utilize aluminum propellers. The main advantage of stainless steel is durability. Stainless props can withstand the damage caused by small rocks, sand and other loose objects in the water. Unlike aluminum, however, steel blades have minimal give. If you hit an object hard enough, there is a good chance you could damage the lower unit. Who of us have not dinged our aluminum props at one time or another? Aluminum blades will almost always sacrifice themselves before causing any motor-drive damage. The prop that came with your boat can very well not be the best performing propeller for your personal needs. Don’t blame the boat and sell it. Change out the prop. That simple change could very well maximize its performance more to your expectations. How do you know which prop to change to? Go to your local boat dealer and talk to their prop expert. The best diameter and pitch can be very confusing and they can put you into a prop that will give you better performance. Current fishing Lake Amador: Despite the weather change and a little rain, it’s still too early for the winter trout planting program. In the meantime, catfish, bluegill and crappie will be your best bet. Fish the points for big catfish and use a big hunk of cut bait in 8-10 feet of water. Chicken liver, mackerel, anchovy and sardines are all working. Dunk crappie jigs around the docks and other structure and you could find a good crappie bite, best early in the morning or late afternoons. There’s an occasional slabside over three pounds to be found. Eagle Lake: The south end of the lake, the deeper end, is showing all the action for trollers going down 50-60 feet. Not many areas of the lake are that deep so head directly to Eagles Nest or Miner’s. By 9 a.m., the bite tapers off to almost nothing so get on the water at or even before the first crack of dawn. Caples Lake: Despite some unsettled weather, the fishing has been good for those who toughed out the weather. With a clearing and warming trend, you should go now for some great rod-bending action. Dunk Power Bait around the dam or cast-retrieve a lure. They’ve caught ‘bows in the five-pound class in that region. Trollers are going down only 25-feet to find brookies, browns and rainbows. Port of Sacramento: Word is that some stripers are beginning to move in. However, most of what you’ll find now is just small fish with a lot of shakers. It will be another month or two before some decent linesides move into these waters. If you want to give it an early start, suspend a big minnow under a bobber. It usually won’t take long for a striper to find it. If you have any questions, comments or concerns, contact George directly at GeorgesColumn@aol.com.