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Inland Navigation 101

Brad Clawson/

(page 1 of 2)

If you've spent any time at all on the inland rivers and lakes of the United States, then you know that boating here is different. The scenery and atmosphere are different. The water and weather are different. Even the boats and some of the boating rules are different.

These differences are a big part of what makes cruising in mid-America so appealing, and challenging. Remember that you must adjust to the conditions; they will not adjust to you. The good news is that with a little practice, patience and good judgment almost anyone can enjoy the thousands of miles of amazing cruising available in our country's interior.

Charts and Other Resources
The use of a chart is recommended at all times unless you're very familiar with the body of water on which you will be traveling. The Army Corps of Engineers is responsible for maintaining the navigable inland waterways, and its charts are available by river and/or river section. They can be purchased as printed sets or downloaded for free online at

You'll see that these charts are marked in river miles, starting with 0 at the mouth of the river and increasing to the headwaters. Specific sites on the rivers are labeled pertaining to their downstream location. So, a marina or lock that is labeled "Mile 5 right descending bank" (or RDB) will be on your starboard if you're headed downstream but on your port if you're headed upstream.

It's also recommended that you get a copy of Navigation Rules, International-Inland, the Coast Guard publication that includes regulations governing the inland waterways (call 202-512-1800). You can probably purchase the book, along with charts for every inland river, for the price of what it would cost to replace one propeller.

Water levels can change dramatically on the inland rivers and lakes due to heavy rain, or lack thereof, and it's a good idea to ensure that you have enough clearance above and below your boat to get where you need to go. Up-to-date river levels and forecasts can be viewed online at and

Water Conditions
With the exception of the Tennessee and the Cumberland rivers, which flow south to north, the inland waterways flow from north to south. Locks and dams are used to regulate the water conditions and help maintain a uniform depth in the navigation channels (typically nine feet). 

These channels can be hundreds of feet wide, with the current only a few miles per hour under normal circumstances. The shallower water on both sides of the channel is often deep enough for pleasure craft. This means that, using caution, almost the entire surface of the rivers and the lower reaches of many of the larger tributaries are accessible.

For normal running, you should stay in the main channel shown by the sailing line on the navigation charts. In straight sections of the river, the channel is usually in the center. Where the river bends, however, the current swings wide and the outside of the curve will have deeper water. On the inside, sand and silt will build, creating shoals. For this reason, it's poor practice to shortcut the bends in rivers.

Anywhere the water's flow is restricted or runs slower, a sandbar is likely to build up. You can expect shoals not only on the inside of bends, but also at the upstream and downstream ends of islands, above and below dams, and near the mouths of tributaries.

The bank itself can be a good indicator of the water depth. Along a high, steep bank you can expect deep water almost to the shoreline. But where a low, sloping beach runs back a long way from the water's edge, the bottom will have a similar slope and may be shallow as much as 200 feet from shore.

Besides knowing where to expect shallow water, it's also an advantage to be able to detect it. Shallow water may often be revealed by a difference in the color of the water, by riffles when the rest of the river is calm or by a patch of quieter water when the rest is choppy.

Inland Boat Handling
When approaching an area where you suspect shoal water, run at bare steerageway, engaging the engine only as needed to maintain headway, and place a lookout on the bow. He or she may be able to see the bottom if the water is clear, or can probe with a boathook or use a weighted line to determine the water depth.

The safest action in shoal water is to cut the ignition at once, safeguarding the propeller and gears. Shifting into reverse won't stop a moving boat in any reasonable distance, and if you do run aground, the damage will be just as great as if the prop were turning ahead.

Another hazard on the inland waterways is floating debris, or drift. Since the rivers drain thousands of square miles, a considerable amount of drift (wood for the most part) is brought down with every rain. Most drift is floating high enough to be seen and avoided by an alert skipper. Slow down. Even in heavy drift, you can plow through safely at lower speeds. On plane, a boat tends to suck in drift that might be otherwise pushed aside.

If you do hear the heavy thump and rattle of the boat hitting a piece of drift, check the hull immediately to see if you're taking on water. More than one boat has been holed by a small chunk of wood spun off by the prop at a high speed. If you notice any unusual vibration, run at low speed to the nearest place where a check can be made for a damaged prop, drive, gearbox or shaft. High-speed operation with a heavy vibration can multiply the damage.

Anchoring and Beaching
From time to time, you'll probably want to anchor or beach your boat for a meal or just to look at the scenery.

To anchor for a short period of time, use a light mushroom anchor of about a half-pound-per-foot of boat length on a 3⁄8-inch nylon anchor line about 50 feet long. Lower your anchor to the bottom after you stop, then let out a length of line equal to about five to seven times the depth of the water as your boat drifts back.

Anchoring overnight on the river is not recommended, as any spot that will allow enough room for the boat to swing on the line will probably put it in the way of a tow (see "Barges and Tows" in this article). Instead, pull into a marina to feel safer.

Never anchor in the channel, particularly at night, as you may be overrun by a tow whose skipper couldn't see you or couldn't stop in time. If you do anchor in an area you think is out of the channel and a tow skipper turns on his searchlight and keeps it shining on your boat, you've anchored in a position where you shouldn't be. Move out as fast as possible.

Beaching is best for an overnight stay, but be wary of rocks or snags as you approach the shore. Come in at bare steerageway with the prop disengaged. Once the bow touches, apply enough power to set your boat firmly on the bank. To secure the boat, attach a line from each amidships or quarter (astern) cleat to a tree on shore at about a 45-degree angle. This will wedge you in place.

You might also set out a stern anchor to keep the wakes of passing tows from driving you too far up on the bank to get off. If you're in a runabout and beach bow-first, be aware that waves from passing tows can come over your transom and possibly flood your boat.

Sep 17, 2014 02:19 pm
 Posted by  birdog

You guys forgot about the Monongahela River that runs from Fairmount, WV to Pittsburgh, PA. The Ohio River is formed at the confluence of the "Mon" and the Allegheny Rivers. Incidentally, Mile Marker 0 for all three rivers is at the confluence of the three rivers. The Ohio River is the only river where Mile Marker 0 is not at the mouth of the river, its confluence with the Mississippi River at Cairo, Illinois.

Geography lesson for today

Just sign me the Old River Rat

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