Lobster pot lines aren’t the only things to avoid while cruising Maine’s coast.
Issue 144: May/June 2022
It had been a gorgeous Maine sailing day up from Biddeford Pool across the wide mouth of Portland, and now, outside Potts Harbor, it was time to turn on Ora Kali’s engine and take down sails. But when I headed into the wind, the engine made a whining noise and the boat barely moved.
Few things are as nerve-wracking as no power when you need it. In this situation, with a wide-open harbor entrance ahead, we weren’t in extremis, and our 1983 Sabre 30 mustered 2 knots with the throttle open and the wind at her stern. But something clearly was wrong. Feeling like an old codger, I crept toward the mooring we’d reserved on the edge of the small fleet.
Rockweed entangles Ora Kali’s prop.
I had learned from an embarrassing incident early in our sailing career to check the prop before jumping to conclusions, so the next morning, when the sun rose high enough to shine through the water, my husband, Tom, and I launched our inflatable dinghy, Evangeline, and I climbed down into her.
Through the glowing green water under Ora Kali, what should have been a propeller looked instead like a huge puff ball. No wonder the boat didn’t move; it must have been like trying to whip cake batter with beaters clogged with dough. “It’s seaweed!” I called up to Tom, feeling vastly relieved. It could have been anything from a lobster trap line wrapped around the shaft to a failing transmission. This should be easy to fix.
Necessity is the mother of invention; Tom and Ann used a kitchen knife taped to a boathook to clear the weed from the boat’s prop.
Tom handed over the spare boathook, but its short, blunt point only rearranged the seaweed strands. So, he taped a kitchen knife to the end, and I patiently unraveled the huge ball and watched it float off strand by strand. The knife didn’t cut the strands, but it created a deep, v-shaped groove that allowed me to grab, twist, and pull, until eventually the clean outline of our two-bladed fixed prop reemerged.
This stringy stuff, with its tough, leathery fronds, is rockweed, also known as asco, derived from its scientific name Ascophyllum nodosum. Ubiquitous on the Maine coast, it drapes like an immense mane across the rocks at low tide and floats in rich forests when the water is high.
Young individuals attach to coastal rock with holdfasts, and as they grow, the plants provide shelter and habitat for myriad marine species. Its fronds average 20 to 30 inches long, with air bladders that form annually like tree rings, helping the plant float upright when the tide is high. Those air bladders also enable it to float freely on the surface if the plant loses its grip on the rocks, whether through storms or human activity (rockweed is commercially harvested). Along with providing habitat for intertidal species, rockweed absorbs CO2, which helps reduce ocean acidification.
A close-up image shows the air bladders that enable rockweed to float.
In Potts Harbor, when we successfully removed the rockweed with our hastily made tool, we thought that would be the end of the story. I made it a point to avoid patches of seaweed as we made our way down east. Two days later, we navigated narrow Fisherman’s Pass en route from Boothbay Harbor to Christmas Cove against a steady stream of boats heading south for the end of the season, and once again, Ora Kali was barely able to make way against a contrary current.
The next morning, we found another prop ball—not as big, but definitely there. Luckily, the boat hook tool was stowed in a locker, and once again I untangled the seaweed.
From there on, even if we weren’t going ashore, we launched Evangeline at every stop so we could check the prop. Under sail, Ora Kali flew along; only when the engine came on at the end of a sail did we have an issue. This was downright nerve-wracking as well as weird, because I certainly never saw enough nearby rockweed to create the balls, so how could I possibly avoid it?
Cruising always presents the possibility of the prop getting fouled, and when Tom and I bought bluewater boats, we looked for skeg-hung rudders with apertures for the prop or full keels. Neither provides perfect protection; on our maiden voyage years ago with Kraken, a full-keeled Kaiser Galeforce 34, we caught a crab pot that had been sucked under by strong currents in Delaware Bay, wrapping it tight enough to stop the prop.
Buying our Ora Kali for coastal cruising, it felt so freeing to have a fin keel that I didn’t stop to consider even the obvious drawback of trap lines, let alone rockweed. But from here on out, it’ll be one more reason to do our best to steer clear of the tangles.
The Takeaway—AH
Several factors contributed to but didn’t cause our seaweed problem. Among them, Ora Kali has a fixed, offset prop, and a Westerbeke 13 engine that is underpowered for our 9,000-pound displacement.
One approach would be to install a shaft cutter. Various makes and models of cutters work on the same principle; a ring of sharp metal clamped around the shaft forward of the propeller is designed to cut through any rope that starts to wrap around the propeller. Shaft cutters appear to be a good solution for boats under power, greatly reducing the likelihood that catching a length of rope will cause damage. But a boat that’s sailing through a field of pots and catches a trap line still has to find another way to get unstuck under sail (this happened twice in the final days of our voyage) when turning on the engine could cause the rope to wrap before it was cut.
Manufacturers generally refer to their products as line and net cutters, and their promotional videos feature cutters slicing neatly through line of varying widths and amounts. But I suspect that shaft cutters would be ineffective against rockweed because the strands snag on the propeller and not the shaft, accumulating over time and bypassing the sharp blades.
One thing we couldn’t decide was exactly when Ora Kali picked up rockweed. From crossing Casco Bay off Portland, we knew the stringy stuff accumulated under sail, but it was harder to tell whether we also picked it up when the engine was running.
Either way, a folding prop might be a solution. (This is another amenity we avoided when bluewater cruising, opting for the solidness of a fixed prop over the complication of gearing and folding mechanisms.) Under sail with the blades closed, a folding prop would provide a slim profile. It might still pick up the odd rockweed strand, but not enough to prevent the blades from opening when the engine is turned on. When open under power, a folding prop would be just as likely to catch rockweed as a fixed prop. Theoretically, going into neutral would cause the blades to fold and the rockweed to fall off, unless it kept the blades from folding.
Ora Kali’s offset shaft is obviously an issue. Sabre Yachts designed their sailboats this way to help with prop walk and to make removing the shaft easier. Although the keel might block some seaweed from a centered prop, this is probably not the only factor. The offset shaft was actually an asset as it made reaching the prop easier. Besides, it’s not something we can change.
The third factor is something we could and may address, and not just because of rockweed. When a boat is underpowered, anything that slows her speed affects her ability to maneuver in close quarters. At the end of a leg, rockweed on the prop can make for a much worse day than we had in Potts Harbor for a boat like Ora Kali trying to maneuver up to a dock or into a slip. And as we saw, on Maine’s coastal route numerous bottlenecks form where boats of all kinds funnel through narrow passes between shallow islets and rock reefs, and tidal currents run strong. A larger engine would push Ora Kali more easily at all speeds. If enough rockweed accumulated on the prop, though, this advantage would disappear pretty quickly.
Ultimately, even if we installed a shaft cutter, a folding prop, and a larger engine, we would carry a version of the knife taped to the boathook. A company called Sailor’s Solutions offers a Hooknife. It’s similar to our tool but has razor-sharp edges not only in the notch but along the sides. Rockweed clearing isn’t so much about cutting as grabbing, twisting, and pulling, and a deep notch that’s slightly sharp or even serrated would be sufficient. Like the Hooknife, this could be made to fit on the end of a telescoping brush handle, and with smooth sides and blunted point, it would not have to be stowed so carefully, making it friendlier to an inflatable dinghy and available for daily use.
Ann Hoffner spent summer 2021 sailing Ora Kali, her Sabre 30, from New Jersey to Maine, where she and her husband, co-sailor, and photographer Tom Bailey, recently moved. She has written numerous articles about their voyages on Oddly Enough, a Peterson 44. The Sabre 3o marks a shift for the couple from bluewater to coastal cruising.
Thank you to Sailrite Enterprises, Inc., for providing free access to back issues of Good Old Boat through intellectual property rights. Sailrite.com
