Streaming North: Cruising Off the Continental Shelf

Article started on Sunday, May 7, 2017 at 6:00 AM

Direct Hingham, MA from Georgetown SC

Overview:

The two day weather layover in Georgetown allowed a massive low pressure system to work its way north and east. As it did, widespread high pressure from the Midwest took its place. The forecasts for our proposed route at departure from Georgetown on Sunday at 6:30 AM indicated 15 to 20 knot winds, mostly out of the southwest and west, with following seas 3 to 5 feet from Georgetown all the way to Cape Hatteras, some 213 nautical miles to the east northeast. For the rest of the 600 nautical miles to Massachusetts, the forecast called for diminishing winds and seas around 2 feet.  

The deep low working its way north

We are now predicting arrival in Hingham at 6:00 AM on Thursday morning May 11^th using existing programmed routes.  If the forecast holds, we will cover a record 813 nautical miles and, for the second time this voyage, run continuously for four days and three nights. This is truly exciting.

Underway:

We departed Georgetown’s Harborwalk Marina at 6:51 AM and headed 13 NMs south down Winyah Bay to the Atlantic Ocean. Our departure at close to slack tide put us in position for a favorable current.

At 8:44 AM we cleared the Winyah Bay Inlet with an average speed of 8.5 knots and, with full consideration for the forecasted winds and seas, programmed a 220 nautical mile route from that took us direct to Cape Hatteras via Cape Fear (Southport NC) and Cape Lookout (Beaufort NC).

Explanatory Note: This route requires rounding three shoals, Frying Pan at Southport, Cape Lookout at Beaufort and Diamond at Hatteras.  This route can be run close to the coast or offshore. Going close to shore significantly increases the distance traveled as the shoals associated with the capes protrude out many miles (11, 12 and 8 respectively). The near shore route is approximately 268 nautical miles as compared to 220 if run in a straight line.  Those 48 NMs translate into 6 additional hours of travel (and 55 gallons of fuel).

At 5:00 PM on Sunday we crossed the Frying Pan Shoal Slue, a marked shortcut through the shoal with at least 20 feet of water. We noted a following sea, a smooth ride and conditions favorable for continuing to Cape Hatteras offshore in a straight line.

We rounded Cape Lookout Shoals at 3:00 AM on Monday noting a following sea and west northwest winds of 18 to 22 knots and headed direct to Cape Hatteras some 68 nautical miles ahead. We had traveled 167 NMs since leaving Georgetown.

Here’s a question to ponder with regard to the name “Cape Lookout.” Did this cape get its name because it was a good place to “lookout” over the ocean or was the name trying to convey a message – “lookout!!!” The folks who named Cape Fear seemed to be very clear with their message – this is a bad spot. Of course the naming system breaks down at Cape Hatteras, which is without question the most dangerous spot on the Eastern Seaboard. If I were given the naming task I’d call it “Cape Hell,” which it has been on three of our north/south voyages.

Calm waters

Guy at the wheel

Good view of our pilot house instruments

At 11:03 AM on Monday Cape Hatteras was “Cape Easy” with north winds at 10 knots and 2 to 3 foot head seas. Our speed had also picked up slightly owing to the Gulf Stream and our distance off shore. We noted in the log that the head sea we were experience might be standing wave action resulting from the opposing forces of the north wind fighting the Gulf’s northerly flow. Fortunately, the low 10 knot wind velocity only resulted in slight pitching. A stronger wind would have resulted in more violent pitching. We think the lesson is stay out of the Gulf Stream in a northerly wind.

Current sea conditions as we make our decision to go direct Buzzards Bay

Current location of fronts and pressure as we are make our decision to go direct Buzzards Bay

Conditions 24 hours later. We have a weather window

Decision Time: Earlier this morning Bob, Guy and myself performed our morning weather review. The forecast noted in the overview (above) for 3 to 5 foot waves at Cape Hatteras with an improving trend to two footers both near shore and offshore as we progressed north was still valid.  The forecast for calm seas stretched several days.  We had a weather window. This resulted in yet another strategic route decision and another all-time first. We decided to head direct to Buzzards Bay Massachusetts from the tip of Diamond Shoal at Cape Hatteras North Carolina (429 NMs).  This route takes us 85 miles offshore when we are adjacent to New York Harbor. By taking this route we shave off 71 nautical miles and 90 gallons of fuel.

Bob and Guy 

The combined saving in distance, fuel and time from going in a straight line from Georgetown to Cape Hatteras and then to Buzzards Bay is 135 miles, 142 gallons and 16 hours.  The distance from Cape Hatteras to Buzzards Bay is 429 nautical miles.  At 8.4 knots we will cover the distance in approximately 51 hours.

Stow-away. A flying fish landed on the flybridge

At 2:45 PM on Monday we were abreast of Oregon Inlet (just north of Cape Hatteras) running 24 miles from shore. While on this segment the winds became light and variable for almost two hours and the seas calmed to a 2 to 3 foot swell. Time to estimate some arrival times. At that moment, the GPS indicated 396 NMs to the beginning of Buzzards Bay. 

Estimate to:

• the entrance to Buzzards Bay: 3:00 PM on Wednesday
• the south end  Cape Cod Canal: 5:00 PM on Wednesday
• Hingham Shipyard Marina: 1:00 AM on Thursday.

We also noted that the current in the Cape Cod Canal will become favorable at 4:30 PM. It will be fun to see how these estimates play out.

Meanwhile, back to the voyage.

On Monday at 8:35 PM we were 76 NMs east southeast of Cape Henry (Virginia Beach) maintaining an average speed of 8.5 knots thanks to the Gulf Stream. Winds were east northeast at 10 knots. That gave us a 2 to 3 foot quartering head sea and a smooth ride. We were now outside the continental shelf in over 3,000 (three thousand) feet of water.

This photo shows we are outside of the Continental Shelf

As we progressed further north into the evening and early morning on Tuesday the winds and seas decreased to the point where we riding on a beautiful calm sea.  When I took 1 to 4 watch there was very little to do but enjoy the serenity of a moonlit night and listen to James Taylor. Most important, the marine forecasts for our route continued to predict optimum conditions.

Calm waters almost 100 nautical miles offshore

At 4:00 AM, when my watch ended, we were 106 NMs south southeast of Cape May New Jersey (at the north side of the Delaware Bay) and 100 NMs east of Cape Henry (at the south side of the entrance to the Chesapeake Bay) in placid waters with no traffic within 24 NMs (according to the radar).

Explanatory Note: Running almost 100 miles from shore and more than 100 miles from a navigable inlet and shelter of a marina or anchorage is serious business. One should not undertake such a voyage without a weather window that covers the enroute period and even beyond. A “surprise” change in the weather does not leave many options when your boat’s cruising speed is 8.4 knots and its top speed is 13 knots with a 50 GPH fuel burn. Heading for shore/shelter is an 8 hour 400 gallon proposition at top speed (assuming you have enough fuel). Bottom line. A trawler like the 63 cannot out-run the weather. The “good news” (sort of) is that the 63 is rated “Ocean A - Unlimited.” She can handle anything - but why.  The other consideration is mechanical reliability. Alongside of aggressive maintenance, we visit the engine room every 4 to 6 hours to verify the working of our machinery.

We had several visits from dolphins

Dolphin off the starboard side

Dolphins riding the bow wave

On Wednesday, May 10, 2017, when my 1 to 4 watch began, we were 90 NMs southeast of New York City and 119 NMs from the entrance to Buzzards Bay. Still way offshore in perfect conditions. Our ETA to Buzzards Bay was now 4:25 PM (Wednesday). When my watch ended at 4 AM it had improved further to 3:41 AM.

Earlier on Tuesday afternoon (15:10 log entry) our speed continued to decrease. We noted a current speed of 7.0 knots, a drop of 1.4 knots from our 8.4 average (which is also the 63s optimum cruise speed). Sirius’ water temperature chart (called “Fishing”) showed us in cold water off the continental shelf. We hypothesized that we were running against the Labrador Current that comes down from the North Atlantic and which causes the Gulf Stream to veer east northeast past Cape Hatteras. Whether that is true or not, it did not alter the fact that we would not achieve our 3:00 PM ETA to the beginning of Buzzards Bay or the favorable push through the Cape Cod Canal that begins at 4:30 PM.

This caused us to consider the impact of the speed decrease in relation to the current at Buzzards Bay and the Cape Cod Canal. Basically, we would reach Buzzards after the current began to flow south, which would result in an average 3.0 knot speed reduction over the 25 NMs to the east end of the Cape Cod Canal. We pondered an immediate increase to our speed. To counter the lost 1.4 knots we would have to increase RPMs to 1700 (9.9 knots). However, the fuel burn at 16 gallons an hour shot that idea down as it almost doubled fuel consumption. 24 hours are needed to cover the 194 NMs to reach Buzzards at 3:00 PM. This would result in an additional fuel burn of 216 gallons (over $500). We concluded that it did not make sense given our projected arrival in Hingham in the early morning hours and the fact that we were not up against a deadline. Further, we again hypothesized that our speed might just increase as we crossed over the Continental Shelf and returned to shallower water.

So back to 4:00 AM and the end of my watch. Our ETA was now 3:41 AM. Was our hypothesis correct? Who knows. But the result is the same. As of this moment, we traverse Buzzards Bay and the Cape Cod Canal on a favorable tide.

We made our first landfall in days when we visually spotted the wind farm off Block Island at 10:35 AM. It was 19 NMs west of our position.  At 12:30 PM we were adjacent to Block Island, 11 NMs to the northwest. Winds were west at 10 knots and seas were less than 2 feet.

Bob watching a pusher tow overtake Guided Discovery

As we approached Buzzards Bay we began seeing fishing buoys and lobster pots. We used these "obstacles" as an opportunity to practice spotting and dodging small objects with our FLIR night vision. Great fun - kind of like a video game.

At 3:51 PM on Wednesday we reached the the entrance to Buzzards Bay and the beginning of the home stretch.  Best of all we arrived just as the tide turned to a northerly flow giving us an increase in speed.

Tide Turning Positive just as we enter Buzzards Bay 

By 6:40 we had reached the Hogs Island Channel, which marks the beginning of the Cape Cod Canal. We saw a 4 knot increase in speed to 12.5 knots and a top speed of 13.5. Note: The 63 can barely reach 13 knots and when it does it is burning 50 gallons an hour. The current was pushing us at our top speed while are fuel burn remained 9.1 GPH. Life is good.

Railroad lift bridge at south end of the Cape Cod Canal

12.8 knots current speed and 13.4 top speed in the Cape Cod Canal

3.2 knot current at the Sagamore Bridge
Current moving toward 92 degrees (a northerly flow)

The Sagamore Bridge as viewed on FLIR night vision

At the east end of the Cape Cod Canal we turned north and headed for Hingham. Five and a half hours later at 1:00 AM on Thursday, Guided Discovery was sitting at the dock. We had hit the arrival time that we predicted three days earlier to the minute.

Heading north from the east end of the Cape Cod Canal to Hingham

Moon rising over Cape Cod Bay 

This amazing voyage was over but, clearly, it was one for the record books. 

Segment Statistics:

• Total Segment Distance: 745 NMs
• Average Speed: 8.4 Knots
• Top Speed: 13.5 Knots        
• Engine Hours: 91
• Engine Fuel Consumed: 872 gallons
• Fuel Efficiency: .85 GPNM
• Generator Fuel Consumed: 93 Gallons
• Total Fuel Consumed: 964 Gallons
• Fuel Remaining: 336 Gallons (186 usable based on a 10% reserve)

Trip Totals

• Total Distance: 1,513 NMs     
• Engine Hours: 174
• Engine Fuel Consumed: 1,667 Gallons
• Overall Engine Fuel Efficiency: .91 GPNM
• Generator Fuel Consumed: 211 Gallons
• Total Fuel Consumed: 1,878 Gallons

Written by Les.