Newbie cruisers and boat owners often learn the dangers of motoring with debris in the water the hard way. Hopefully, this helpful tip will keep your engine going without fail.
Spotting Trouble Before It Happens
Once, while motoring back to Boot Key Harbor after the wind died, we ran across a couple of huge patches of very coarse grass floating on the water. It almost looked like large pine needles.
From past experience, we knew to watch the engine temperature closely. Sure enough, we saw it creep up just a couple of degrees. It didn’t go into a danger zone, but we knew we had to check the raw water intake as soon as we got to our mooring.
It was almost totally full of the grass.
The good thing is that the grass was coarse enough that it hadn’t totally stopped the flow of water. We’d only motored about 15 minutes after encountering it, but if we’d been going very far it might have restricted flow sufficiently to cause the engine to slowly overheat.
From Bad to Worse
An hour or so after Dave had cleaned out the raw water strainer, I jumped in the water to clean the bottom of the boat. Visibility isn’t great here and all of a sudden I saw what appeared to be a tree branch sticking out of the hull. Huh??
It was a big clump of the grass that had been partially sucked into the engine water thru-hull. There was so much that it hadn’t all made its way in. It had just gotten stuck there. I pulled two big fistfuls out. Yikes! The problem was even worse than we first thought, and I’m very glad I just happened to decide to clean the bottom before we went out again. Note to self for future: when the sea strainer is really clogged, check the thru-hull too.
Other Debris Dangers to Your Boat Engine
It’s also easy to suck up plastic bags. Many cruising locales have a litter problem and bags that blow into the water can cause huge difficulties for boaters. We know of numerous people who did so in the Sea of Cortez. While it can happen anywhere — all is takes is one bag — be very aware of engine temperature if you encounter a patch of litter.
When Boat Debris is a Regular Occurrence
Anyone who has traveled the Great Dismal Swamp knows that duckweed is a hazard to navigation, particularly in the autumn. Boaters frequently mistake it for algae. It’s actually dense mats of tiny green plants.
At times, the threat is so severe that the Army Corps of Engineers issues warnings to mariners, reminding them to check their raw water strainers. You absolutely want to keep an eye on your engine temperature gauge while traveling the ditch. In addition, pay attention to fellow cruisers in your area on social media. They will often give a heads up when encountering this thick mat of plants floating on the surface of the water. And remember to follow the Dismal Swamp Welcome Center on your favorite social sites.
Although many cruisers don’t stop there, Douglas Landing, located halfway between the visitor center and Deep Creek Lock is a good place to stop and check your raw water strainer. The lock is large enough for several boats, and offers nearby flush toilets and access to walking trails. It’s a great place to walk your dog, in addition to taking care of your boat.
Because the ICW is a protected waterway used by both commercial vessels and pleasure craft, some cruisers underestimate its challenges. It’s why we created the ICW Quick Reference Cruising Guide. Its easy table format offers bridge information, storm protection, free docks, inlet guidelines, and provisioning options, and more saving you hours of research each night. Oh, and it includes information about free docks, like Douglas Landing, where you can walk your dog, stay for the night, or stop just long enough to clean out your raw water strainer.
Advice from Fellow Cruisers
Cruisers who frequently encounter debris (Sargasso grass is a major hazard in the western Caribbean), consider modifications to keep their engine safe. Boat owner, Stephen recommended a detailed article by Steve D’Antonio on the shortcomings and strengths of various cooling water strainers. Peter B. installed an Aqualarm sensor (Amazon), and claims it has saved his boat several times.
While my experience has mostly been with plant matter, Erin M. shared that her boat picked up sea nettles (jellyfish) in their raw water strainer while motoring in the Chesapeake Bay and Patuxent River. An additional hazard is that this sea debris stings, so be careful cleaning out your strainer basket if you encounter them.
Final Thoughts on Motoring with Debris in the Water
Whether you encounter annual growth or stray debris in the water, always keep an eye on your water temperatures. Be prepared to empty your strainer. And, if you’re in a place where it’s safe to do so, considering checking your thru-hull from the water. The last thing anyone needs is to have their engine fail when they need to rely on it.
Carolyn Shearlock has lived aboard full-time for 17 years, splitting her time between a Tayana 37 monohull and a Gemini 105 catamaran. She’s cruised over 14,000 miles, from Pacific Mexico and Central America to Florida and the Bahamas, gaining firsthand experience with the joys and challenges of life on the water.
Through The Boat Galley, Carolyn has helped thousands of people explore, prepare for, and enjoy life afloat. She shares her expertise as an instructor at Cruisers University, in leading boating publications, and through her bestselling book, The Boat Galley Cookbook. She is passionate about helping others embark on their liveaboard journey—making life on the water simpler, safer, and more enjoyable.
The Boat Galley says
Our previous boat had one but not this one. And good point about which way around they should go.
Kristine Henson says
Good advice!
The Boat Galley says
Unfortunately it is in all too many places.
Carolyn Shearlock says
There’s still a lot of crud that’s 6 inches or more under the surface!
The Boat Galley says
Yes, it’s not just a #Matthew problem!