Monthly Archives: February 2018

Prop Pitch Matters

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Terrapin prop after re-pitching

When you run a boat under power, the prop size and pitch needs to be matched to the maximum speed of the boat as well as the maximum rated RPM of the engine.  In other words, at wide open throttle (WOT), the boat should reach its maximum (comfortable) cruising speed and the engine should be operating at its rated maximum RPM.

Our PDQ 32 LRC has two Yanmar 2GM20f Diesel engines, each rated at 18hp at a maximum RPM of 3600.  So, at WOT, the engines should be able to operate at about 3600 RPM and the boat should reach a speed of about 7 knots.

When we bought the boat, she had upgraded 3 blade props (considered more efficient and smoother than the stock two bladed props).  However, when motoring on smooth water, the engines would only achieve 2800 RPM at WOT.  In addition, there was smoke in the exhaust indicating the engines were laboring too hard.  The analogy would be driving a car up a hill in 4th gear.  The car would go, but the engine would be lugging and operating at a suboptimal RPM. If you downshift, the RPM goes up, you have more horsepower, and the car runs more smoothly.  The term for this in boats is being over-propped. This is due to the pitch of the prop being too steep.

Fortunately, there are propeller specialist shops that can re-pitch props and they have sophisticated computer programs to determine the optimum prop pitch based on your boat, transmission and engine.  I used Coastal Props in Fort Meyers.  The existing props were 15” in diameter with a pitch of 12. After consulting with Coastal Props they ran the info through their program and decided that the pitch needed to be reduced to 9. I removed the props when the boat was on the hard, sent them to Coastal Props and they re-pitched, balanced and polished the props for $135.00 each, a bargain.

The improvement in engine performance was dramatic. I can now get almost 3600 RPM at WOT and comfortably cruise at 3200 rpm, much closer to the peak HP of the engines. The engines run much more smoothly and no more smoke! Diesel engines also need to periodically be run at their max rated RPM to burn off carbon from the valves and exhaust. The re-pitched props now allow me to do this.  Thus, for a small investment, I believe I have greatly increased the life of the diesels on Terrapin.

Hurricane Irma

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In early September, 2017, hurricane Irma cut a swath across the Atlantic and Caribbean as a cat 5 hurricane causing extensive destruction in the Leeward Islands, the BVI, USVI, Cuba and the Florida Keys before it turned North up the West  coast of Florida.  We watched in horror from our home in Lexington as Irma carved a direct path up the West coast of Florida toward Terrapin.  However, I knew I had done everything I could to  protect Terrapin from this eventuality.  In May I had put Terrapin in a storage yard called Safe Cove Boat Storage.  Safe Cove is within a canal system well inland from the Gulf and so was pretty protected from storm surge.  I also paid extra to have Terrapin tied down to concrete blocks with straps.  I had also removed all sails, most of the running rigging, and all canvas.

Hurricane Irma

Luckily, Irma weakened to a cat 3 as it  made landfall in Florida.  It moved slightly to the East of Punta Gorda and ended up causing minimal damage to that area.  There was no damage to speak of in Safe Cove in spite  of high winds.   Even if Irma had  hit Safe Cove with more force, I feel that Terrapin would have had a fighting chance.  The last time a hurricane hit the Punta Gorda area was 2004.  Hurricane Charlie did extensive damage to Punta Gorda and areas surrounding Port Charlotte.  So, i will continue to tie down Terrapin in Safe Cove and hope for the best.  She is insured.

 

Location, location, location

Terrapin in Fisherman’s Village Marina (this is before we changed her name)

Christmas in Fishville Marina

We looked at boats on line all over the country.  I had pretty much narrowed down the boat I wanted to the PDQ 32 (more about that in another post).  But where to locate the boat?  As commuter cruisers, we plan to maintain our home in Lexington Ky, and I will continue to work at the University.  We considered buying a boat in the Caribbean and keeping it in a marina there, moving it to  Grenada for hurricane season.  However, the logistics of getting back and forth to Lexington were formidable.  After spending some time in Sarasota and checking out the West Coast of Florida, we realized that we  have beautiful sailing grounds right in our own backyard, so to speak. The “aha moment” came when we realized that Allegiant Air flies non-stop from Lexington to Punta Gorda 5 days a week with really cheap fares.  So, it made perfect sense to locate the boat in Punta Gorda.  This narrowed our search to the East Coast of the US and the Gulf Coast.  If I found a boat in this area, I could easily sail it to Punta Gorda, although sailing from the Northeast would take some time.  As it happened, a boat came up for sale in Sarasota, and the sellers were happy to move it to Punta Gorda for us to inspect.  After going through the inspection, purchase, registration, identifying a marina, storage, etc, it was invaluable to be able to easily travel from Lexington to Punta Gorda in 2 hrs.  With respect  to a marina and boat storage, I think we were extremely lucky.  Punta Gorda has a fantastic marina called Fisherman’s Village Marina.  We were lucky enough to secure a slip for the season (November through May).  Then we located a great boat storage yard called Safe Cove, which is a 2hr sail across Charlotte Harbor in a freshwater canal system.  I can’t imagine trying to do all this in the Caribbean in a foreign country.  I know a lot of people  do  it, but I’m not sure everyone thinks it through.  Location matters!