Streaming North: Confidently Cutting Close on Fuel

So it’s 1:00 AM on Thursday morning and were headed for Charleston as I take over the 1 to 4 watch from Bob. We had been watching the weather closely throughout the trip and suspected that we may run into stormy weather as we headed north. After making the 1:00 AM log entry and performing an engine room check, I focused on the weather for Cape Hatteras, the most challenging stretch of water on the entire 1600 NM voyage. Below is what a saw:

The forecast for Cape Hatteras to Ocracoke Inlet showed that starting on Thursday night wind and seas would continue to increase pretty dramatically. This was due to the formation of a deep low pressure system over Alabama and high pressure over New York that was drifting slowly east into the Atlantic.  This combination coupled with a frontal passage at Cape Hatteras foretold extremely rough seas over a wide area.

Deep low pressure over Alabama drifting east with high pressure over New York slowly lifting into the Atlantic

Cold front approaching the coast in 48 hour

As noted in the forecast photos above, the conditions at Cape Hatteras would not improve until late Sunday. Monday's forecast called 2 to 4 foot seas, which is great for traversing Cape Hatteras. Stopping and waiting for the weather to clear was clearly in the cards,

Explanatory Note: My decision to head further north on minimal fuel reserves is based on three years of experience with the 63. That experience includes two ECU adjustments by Caterpillar to correct a discrepancy that showed fuel consumption readings below the actual amount of fuel consumed. It also includes fill-ups after runs in excess of 600 miles where I was able to predict the amount of fuel added with 20 gallons in each 500 gallon tank (A .04% error rate).

Decision Time: At 9:25 AM on Thursday, Bob and I (yes, again, Guy was sleeping) made a decision to head for Georgetown South Carolina where we planned to stay for at least two days waiting for the weather to improve. This decision, which put us at or below the 10% fuel reserve, had several major components:

1. At 9:22 AM we were sitting on 220 gallons of fuel as measured by the site glasses on the fuel tanks. The tank tender's "worst case" measurement was 126 gallons (see Explanatory Note below).
2. The additional distance to Georgetown was 65 nautical miles. That translates into approximately 75 more gallons of fuel consumption.
3. A forecast for 4 to 6 foot seas in the late afternoon between Charleston and Georgetown.
4. Current wind conditions were southeast at 22 knots. This would produce a sea on the starboard forward quarter and a relatively stable ride owing to the stabilizers.
5. The 13 NM run up Winyah Bay would be on calm water reducing the risk of an engine stoppage from unporting a fuel line
6. The marinas in Georgetown are in protected waters - critical as storms were approaching from the west.
7. Heading to Charleston City Marina (aka the Mega Dock) would add 13 nautical miles from our arrival point at the inlet (and another 13 nautical miles to return to sea)
8. Diesel fuel price at Georgetown was $2.27 versus Charleston at $2.74. 

At 9:50 AM we changed course for Georgetown just south of Charleston channel. We had covered 705 nautical miles since leaving Sarasota four days earlier. Our current speed was 8.0 knots (as we were out of the Gulf Stream). The engine monitors showed 720 gallons of fuel consumed. Add to that approximately 72 gallons of generator use and we have a total fuel burn of 794 gallons.

Five hours later, we arrived at the Winyah Bay inlet and headed north up the bay to Georgetown. 

Approaching Harborwalk Marine in Georgetown
You can barely see their Phillips 66 sign

Finally, at 5:23 PM we arrived at the Harborwalk Marina fuel dock. We were greeted by Larry and promptly started the process of refueling. Note: Larry gave me a $2.17 fuel price based on an expectation of over 1,000 gallons.

When fueling was completed we had taken on 1,205 gallons, which includes refilling the auxiliary tanks. So to fully understand our fuel situation we need to focus on the 960 gallons of fuel in the main tanks at the start of the trip.

Recall that we left Sarasota with 960 gallons in the main tanks (500 gallons each) and 31 gallons in the auxiliary tanks (which were essentially unusable). That translates into 480 gallons in each main tank. At Harborwalk I added 468 gallons to port ad 466 gallons to starboard.  The site glasses overstated fuel remaining showing port with 50 gallons remaining and starboard with 60 gallons. The Tank Tender showed port with 21 and starboard with 29 gallons remaining. No question that we cut it close (with at least two hours of running time left if you go with the Tank Tender readings). Again a calculated risk, which in this case included total confidence in the fuel consumption data put out by the engine monitors and the fact that the last hour of the trip was on the calm waters of Winyah Bay.

Guided Discovery at Harborwalk Marina with approaching storm clouds

Summary: This trip established many new records: 

• The longest distance traveled (766 nautical miles)
• The first trip around the Florida keys (with the 63)
• The most fuel purchased at any one time (1,205 gallons) 
• A fuel price within 4 cents of the lowest price we've paid since acquiring the 63.
• The first "ride" in the Gulf Stream
• The fastest enroute speeds
• The shortest time enroute. We were 19 hours ahead of schedule when we arrived at Georgetown inlet.
• The first trip in three years with with down time due to weather (2 days)
• The lowest amount of fuel  remaining at trip end.

Statistics:

• Total Distance: 766 nautical miles (740 since the Venice Inlet)
• Average Speed: 9.4 knots
• Maximum Speed: 14.9 knots
• Engine Hours: 83
• Engine Fuel Burned: 795 gallons
• Generator Fuel Burned: 100 gallons
• Total Fuel Burned:  895 gallons
• Fuel Needed: 1,164 gallons (895 + 269 gallons to fill the auxilliary tanks)
• Fuel Purchased: 1,205 gallons
• Fuel Cost (at $2.17 per gallon): $2,614.8

Written by Les.