Remote Inspection Cameras

A relatively inexpensive endoscope can reveal what lies behind lockers and under cabin soles.

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The most valuable inspection tool will always be 20/20 eyesight combined with experience. But there are times when you can’t lay eyes on the problem. Perhaps you need the rating of an electrical breaker, but you can’t get see through the bundles of wires. Or you’re inspecting seacocks and hose clamps, but you can’t see the backside. Or the prop is vibrating and you wonder whether it is hard growth, rope tangled on the shaft, or a bent blade. Or perhaps you suspect a leak behind the hull liner … the list is actually quite long.

Sometimes shoving a cell phone into the blind spot and snapping some pics will do the job.  It can be expensive if you drop the phone. Also, holding the phone and working the buttons with one hand while reaching into a dark hole can be a real challenge.

Diving is the old school way to inspect a prop or dirty bottom. But the water can be cold, harbor water can be nasty, and some people are not accomplished swimmers or comfortable in the water.

An endoscope (a small lighted camera on the end of a cable) can solve all of these problems.

Non-destructive testing can reveal hidden corrosion. Ultrasound can tell you if the mast base, metal tank, or metal hull is corroding (see PS, November 2018 “DIY Materials Testing”). But even experienced operators will tell you that looking at both sides is better, and that is where remote viewing comes in.

GoPro On a Stick

The newest GoPro devices can stream over WiFi, but  this won’t work underwater. Water absorbs 2.4 gHz radio waves and the signal will vanish under just an inch of water. Without live streaming you can record video, but it will take a number of attempts to actually film what you need, from the angle you need. An underwater extension cable (~$179) solves the problem (www.cam-do.com/products/underwater-wifi-extension-cable-for-action-cameras). Obviously, you need a selfie stick. Complete kits like the one at left, are available.

Endoscopes

A few decades ago endoscopes were too expensive for an amateur user to justify buying. Today there are many inexpensive wireless endoscopes, no bigger than your pinky. They use the same tiny camera tech found in cell phones, surrounded by a ring of adjustable LED lights, linked to a base unit by a 10- to 20-foot cable (increase to  50-100 feet for another $10-$30).

The base unit at the opposite end of the cable connects to a smart phone or lap top via WiFi or mini USB. Commonly, the focal length is fixed at 1.5-4 inches, perfect for inspecting small items in tight places.

Remote Inspection Cameras
1. The endoscope reveals the condition of hiddin fiberglass bulkhead tabbing.
2. LED lights surround the tiny lens. The diameter is smaller than a pinky finger.
Special Precautions for Underwater Repair or Inspection
Remote Inspection Cameras
The precautions you take before jumping into the water to inspect or clean your boat will be different depending on where the boat lies. Along with the man-made hazards of electrical leaks and sharp edges, marine life can also present a danger.

At some point in your cruising life, it is likely you will have to go into the water to deal with a  rope, line, or net that has wrapped around your prop.

The first indication of a snagged line is often a sudden and pronouced increase in noise and vibration in the engine room. The typical first response after putting the boat in neutral is to check the shaft coupling. These have been known to work loose.

If there’s no problem with the coupling or engine mounts (another common cause of excessive vibration), the prop becomes a suspect. If an inspection­—camera or visual— shows a rope around the prop, you should try to remove it before it jams farther around the shaft, or damages the cutless bearing.

We’ve been able to use a hook-shaped cutter attached to a boat hook to cut away discarded fishing gear from the deck. But on other occasions, we’ve had to take the plunge. Before going in the water to address any underwater problem, you need to take certain precautions. 

At the Dock

  1. Lock the prop, and/or take other measures to prevent the engine from accidentally starting. Keys must be out of the ignition.
  2. Electrical Shock Drowning (ESD).This is primarily a freshwater problem caused by wiring leaks. Even a tiny electrical field can paralyze swimming muscles and cause rapid drowning. In freshwater, do not dive at the dock; move at least 200 feet away from all power sources. In seawater it is probably sufficient to unplug your boat, and if possible, all neighboring boat (see “Preventing Electric Shock at the Dock,” Practical Sailor, August 2019).

Anchored, Moored, or Underway

  1. Stop, obviously. Adjust heading to calm the waters in the dive zone by heaving to or streaming a sea anchor. Drifting is generally better than anchoring if there is sea room. Pitching can result in the boat slamming against the swimmer; a helmet may help, but most provide too much flotation and snagging is a risk.
  2. Strong swimmer’s only. This is not just splashing at the pool. Even at the dock there will be a lot of treading water and breath-holding involved. It is possible to become snagged. Underway there will be waves, so experience snorkeling and swimming in surf is mandatory.
  3. Dress for the water temperature. No amount of gritting you teeth is safe below about 68F. A wet suit is better for swimming, but a dry suit works well if you get ALL of the air out (the final seal must be made in the water).
  4. Minimize snag potential. All clothing must be snug. Do NOT put tools on wrist lanyards if free diving; it is far better to drop a knife than to snag your wrist on the prop. Work in shallow water, or tie lanyards to the boat—not the wrist.
  5. Take your time. It is possible to pass out during extended breath holding underwater, and the combination of treading water and working hard can challenge the strongest swimmer. If you are out of breath, take a break. Dangling a flotation aid in the water for rest is a good idea.
  6. Don’t tie a safety line to the diver. It is far too easy for it to become snagged.
  7. Do trail a safety line in the water. A Lifesling is very good for this. If the sailor drifts away and the boat is disabled, recovery will be difficult.
  8. Like much of sailing, judgment is required. Consider all of the variables, the seriousness of the need, and know your limitations. We’ve had to replace a prop while underway offshore, but we had enough time to plan. With patience and good planning, much is possible, and everyone will be safer. Never rush.

Uses for endoscopes

Uses are limited only by your needs and imagination:

  • Checking centerboard trunk, internal and hidden external areas. Cracks and minor leaks are common. How about a good look at the pendant and attachment points?
  • Investigating behind a panel before equipment installation. Who hasn’t dreaded cutting a hole, fearful of accidentally cutting through a bundle of wires or into some structure or equipment you didn’t know was there? If you drill a ½-inch hole, tape the scope to a length of coat hanger with a gradual 90 degree bend, you get a full hemisphere view of the area behind the ceiling or bulkhead panel.
  • Fuel and water tanks. Access is often restricted to a hole for sensors and the fill pipe. With clever use of extensions, you can peer under and around baffles. You can even inspect with the tank full. Diesel might shorten the life of the scope, but they are cheap and replaceable if it does.
  • Hull corrosion. External hammer and ultrasound testing is not good at detecting pitting near frames, and often key frames are hidden beneath finish joinery.
  • Sumps. Our test boat has a sump pump that is impossible to see.
  • Seacock, hose, and clamp inspections. Can you see all the way around?
  • Prop. Strap the camera to a boat hook and take a peek. A GoPro with an extension might be better for this job.
  • Stuffing box. Inspecting this can be agonizing on some boats.
  • Electrical panels. Even with the panel open, often it’s easier to read spec of the sides of breakers and components with a scope. De-energize the panel first.
  • Inside spars. Tangled internal reefs and snagged halyards. Sometimes taping it to a working halyard can help guide it up and down. Tape a string along the side so you can pull it through
Remote Inspection Cameras
1. The focal range on the devices we tested was only 1.3 to 4 inches.The image here is two feet away and out of focus.
2. Remote imaging can be handy at home, too. Through a small hole drilled in a wall, we were able to identify a plumbing leak.

Upsides

  • Compact. 0.7 cm diameter by 3.5 cm long, plus cable. A ½-inch hole is all you need.
  • Waterproof. Generally a minimum of 1.5 meters, but check.
  • Integral lighting. Brightness is adjustable.

Downsides

  • Difficult to manipulate. If the scope twists, it’s like working with a mirror image. Go slow, and try to visualize looking through the camera’s “eye.”
  • Limited focal range. Beyond 1.5-4 inches images are blurry and probably not well-lit. The image size is only 1 square inch. This works for detailed inspection, but not viewing wide areas.
  • Instructions. Details for phone or laptop set-up can be annoying. No way around this.

Endoscope Accessories. Many come with extension kits, but we’ve been happier with DIY solutions. Velcro straps are provided, but tape snags less in tight areas.

A coat hanger can be bent to any curve, making the lens easier to aim. A tiny 90 degree mirror can be handy for peering into shallow spaces as a check before cutting a larger installation hole; kind of like using a tiny periscope to look inside a tightly enclosed space.

Products. There are too many products to review and offerings are constantly changing. We tested a DB Power WiFi endoscope sold on Amazon. Although it is no longer available, there are others like it from various makers.

Features to look for

  • Waterproof. IP68 means more than 1 meter for more than an hour, but how deep is manufacturer specified (1.5 meters is common).
  • Length. At least 10 feet, but more than 15 is only useful if you’re snaking the mast. Ours is 20 meters, and the long cord often gets in the way.
  • Focal distance. 1.5-4 inches is common.
  • Light. Brightness must be adjustable.
  • High definition. 2 megapixels minimum.
  • Phone screen preferred. Endoscopes with integral screens are harder to manipulate and view than phones connected—wirelessy or wired.
  • Boroscopes. Shorter units with integral screens and flexible wands of 18-30 inches have long been a mechanic’s standard. Optimized for looking inside cylinders and other engine spaces, they don’t serve the varied uses of sailors as well as the longer endoscope.

Conclusions

We’re old school, and we like to lay eyes on a problem if we can. If that means changing into trunks or donning a dry suit we will. On the other hand, more than a few times we would have paid good folding money to get my head behind an electrical panel, under an engine to see previously blind fasteners, behind the hull liner, or in some inaccessible bilge space. Oh, the hours of struggling boat yoga, and uncertain puzzling an endoscope could have saved. It’s the kind of tool that can pay for itself in a single use if it solves a problem.

Darrell Nicholson
Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 50 years. Supported entirely by subscribers, Practical Sailor accepts no advertising. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida. You can reach him by email at practicalsailor@belvoir.com.

1 COMMENT

  1. I am looking for a rudder expert who can explain why my brand new Hanse 508 turns aggressively to starboard under motor but not when under sail.
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