Blog 2021

Using A Tide Table

 Based on article by Mel Neale for Boat US

Tide tables tell you three important things for any given place: time of high tide, time of low tide, and heights of each. Here's how to figure out the times in between.

When you need to know approximately how much water is below your boat for a particular time of day, in a particular place, and you have access to the tide tables, the "Rule of Twelfths" will serve you well. It's an easy-to-use guide for "semi-diurnal" tides, which means there are two nearly identical complete tidal cycles a day (high, low, high, low, all within approximately 24 hours).

Basically, it takes about six hours for this tide to completely rise (flood) or fall (ebb). The "slack" period (when the tide is reversing directions) varies in duration depending upon your location, the stage of the moon, the force of the wind, and other factors. Slack tide may last only a few minutes or much longer, and doesn't necessarily correspond to the exact time of high and low tide.

The times of high and low tides, as well as tidal heights above or below chart datum (the numbers showing depths on your chart) for each day, can be determined from a number of sources, such as weather broadcasts, tide tables, navigation programs, some charts, and books such as Eldridge Tide and Pilot Book, published annually. If you're coastal cruising, keep a print version of the tide tables aboard for times when electricity and Internet connections are unavailable.

Find the NOAA tide tables for free at tides and currents.

For simplicity, let's use a 6-foot tidal range (range = difference between high and low tide heights). The range should be divided into 12 parts: 6 divided by 12 = half a foot. The tide will rise or fall one-twelfth in the first and sixth hours, two-twelfths in the second and fifth hours, and three-twelfths in the third and fourth hours.

Wind can affect tides by "piling water up" in or out of a short creek, or up, down, across a broad bay. When blowing for long fetches across the ocean or bays, wind can cause deeper water along the beach, and vice versa.

Keep in mind that all this is approximate and can be affected by phenomena such as high winds and storm surges. Also, in some parts of the world (for example, most areas of U.S. Gulf Coastal States, eastern Mexico, and some Caribbean Islands) tide cycles are "diurnal" (only one 12-hour rise and fall in each 24-hour period). Diurnal tidal areas often have weak currents with long periods of slack and little tidal range. Some areas have a mixture, where highs and lows are unequal and irregular. You will see this reflected in the tide charts. There are other exceptions where wind plays a predominant role, and depending on which way it is blowing on the water's surface, can make depths different from what you see in the tide tables. Always combine what the books say with what you observe around you

In order to avoid capsizing, you need to understand what causes vessels to capsize.

What causes boats to capsize?

In a word, instability. Boats are inherently stable until something causes them to become unstable. And that something is weight — where it is and how much it is determines when a boat will tip over far enough to capsize or fill with water.

A capsize is defined as a boat rolling over onto its side or completely over; swamping typically means that a boat fills with water (often from capsizing) but remains floating. So to simplify, we'll use the term capsize from here on. As mentioned, boats capsize because they become unstable, but there are three main reasons for that instability: too much or unbalanced crew or equipment weight; leaking water, which also creates too much weight; and bad weather, which causes instability as a boat is rocked and filled with water.

We Hope It Floats

There is always a very real possibility of injury when passengers unintentionally go in the water with nothing to hold onto. The U.S. Coast Guard (USCG) has addressed this by requiring monohull powerboats built after 1972 under 20 feet in length to float when filled with water. This is a good thing, because without it, most of the small boats in the study would have sunk out from under the crew, leaving nothing to hang onto while waiting for rescue. The bad news is that boats larger than 20 feet that don't have built-in flotation will eventually sink if capsized, and even smaller boats with flotation can still sink if grossly overloaded. (Note: Boats up to 26 feet built to the American Boat & Yacht Council (ABYC) standards adopted by the National Marine Manufacturers Association (NMMA) also have flotation). Inboard and sterndrive boats have less rigorous basic flotation requirements than outboard-powered boats. If your boat was built before 1972, it wasn't required to — and probably won't — have flotation at all.

Which Boats Are More Likely to Capsize?

Small boats are most likely to capsize. Almost 10 percent were 8-footers, mostly dinghies, and capsizes here often didn't cause much damage. But the biggest group, according to a BoatUS study were the 15-19 footers, representing 41 percent of all capsizes. These boats were typically fishing boats, often with large, hard-to-drain cockpits, sometimes out in poor weather, and were sometimes overloaded.

The next most common group are boats in the 20-24-foot range, representing a quarter of the total; half of those were outboard-powered 22-footers. Larger boats tend to be more stable and rarely capsize, though there were several boats over 38 feet that capsized.

Why They Capsize

Nearly all capsizes can be assigned one of three causes. The most common is too much or poorly distributed weight. Small boats are much more susceptible to an extra person or two or a couple of heavy coolers aboard than larger boats. Older boats especially may have gained weight over the years as more gear is stored aboard. On boats with cockpit drains, an extra beefy friend or a second cooler might be all it takes to make the water come back in through the drains, filling the boat. While most of these under-20 foot boats are required to have flotation, they also must have a capacity plate that states how much weight and how many people can safely be aboard. Pay attention to this number, and keep in mind that the number of seats in a boat is not always an indication of the number of people it can carry safely. Exceeding the capacity limits, even in calm water, is asking for trouble; and in many states, operators can be ticketed for it. All it takes is a stiff wind, a large wake, or an unbalanced load to flip over.

The bottom line is that loading too much cargo or too many passengers in one part of the boat can affect its stability, even if the total load is within the boat's maximum capacity. Weight needs to be evenly distributed, especially in smaller boats. One other thing worth mentioning is that capsizes can also be caused by modifications that affect the stability of the boat. Even a small tuna tower can severely change the center of gravity, especially on a smaller boat.

The second major cause of capsizing is leaks. Sometimes it's as simple as forgetting to put the drain plug in; other times it's leaking fittings. Water sloshing around in the bottom of the boat affects stability and waves or a wake can cause it to flip. Tying the drain plug to your boat key is a simple way to remember the plug. On the other hand, leaking fittings that can fill the boat with water are usually out of sight, often in livewells and bait boxes. Several claims were reported when an owner installed a livewell fitting using cheap PVC pipes and valves, and at least one livewell had no shut-off valve at all with no way to stop the ingress of water once it began leaking. Any fitting that penetrates the hull needs to be closeable and should be made from stainless steel, bronze, or Marelon. One more thing the claims revealed: Some livewells are plumbed in such a way that they'll flood the boat if the valve is left open while underway.

Many older outboard-powered boats have low transom cutouts that can cause the boat to flood simply by slowing down too quickly, especially with excess weight in the stern. Newer outboard boats have a well that reduces the risk.

Some boats have cockpits that drain into the bilge (generally considered a poor design), requiring the use of a bilge pump to even stay afloat. Bilge pumps are designed to remove nuisance water only, not to keep a boat from sinking. If your boat's cockpit drains into the bilge, be aware that if the bilge pump fails, your boat can fill with water and capsize or sink.

Weather is another major cause of capsizes, sometimes in concert with overloading. Small boats are easily overwhelmed by modest waves or even wake, especially if they've got a full load and sit low in the water. A sudden squall can flip even a larger boat. Check the weather forecast before you go out, and keep a weather eye on the sky. In most areas, NOAA broadcasts continuous weather via VHF radio. If you're within range, smartphone apps can show you detailed weather maps, including radar, which can indicate approaching storms. Weather changes quickly on the water, so at the first sign of bad weather, head back to the dock. If you're caught out in a squall, have your passengers stay low near the center of the boat to maintain stability.

Based on an article in BoatUS

I’m often approached with questions concerning lean and list and heal.  A boat not riding on its lines is dangerous, and very uncomfortable, not to mention its maneuverability is curtailed.

 Here are some reasons for list and some things you can do to alleviate the problem.

Weight
If your boat lists at rest, there is too much weight on one side. It could be gear or it could be water trapped in a stringer bay.

Suggested Solution: Investigate. Take inventory. Re-balance supplies; reposition crew if underway. Address water ingress and drain or dry.

Prop Torque
It’s normal for a right-hand-turning prop to cause listing to port in a single-engine application. The reason is that a prop is most efficient in the upper, down-moving quadrant of its rotation (between noon and 3 o’clock for a right-hand propeller) and so creates more lift on the starboard side; thus the boat lists to port.

Suggested Solution: Trim out more once on plane. The further from perpendicular to the boat the rotation gets, the less listing leverage it can exert. Use a prop with more pitch (within rpm limits).

Wind
V-hulls can tend to lean to windward. This results from turning slightly into the wind to maintain a straight course. Also, prop torque results in more lean than on flatter-bottomed boats.

Suggested Solution: Shift supplies or crew. Use trim tabs. Alter course (if possible).

Engine Trim
Running with the drive trimmed in exacerbates prop torque.

Suggested Solution: It’s correct to trim the engine in when achieving plane. But up and running, trim out to lift the bow, and, as it pertains to listing and heeling, reduce the effect of prop torque

Signs of heat exhaustion to keep in mind this summer to avoid health hazards

Unfortunately, I see this all to often. Take a moment to review and stay safe in the heat- no matter how old you are.

As the temperatures rise, they pose a threat to people who are unaware of heat exhaustion. Heat exhaustion is a condition that occurs when your body overheats, causing a variety of symptoms. As you and your family enjoy the summertime heat, it is important to remember these causes, symptoms and treatments of heat exhaustion to avoid a potentially life-threatening situation.

Causes

When the temperature rises in the summer, the body is made to cool itself in a variety of ways. The body’s main method of self-cooling is through sweating. As sweat evaporates, it allows your body temperature to stay regulated; when sweat production is unable to cool the body down enough, heat exhaustion sets in.

Heat exhaustion is typically seen in people exercising strenuously in hot weather. According to the Mayo Clinic, it can also be caused by dehydration, which reduces the amount of sweat that can be produced; alcohol use, which affects the body’s ability to change its temperature; and wearing too many clothes.

Symptoms

Symptoms of heat exhaustion can occur quickly or can develop overtime, depending on what is causing the heat exhaustion. Typically, though, the symptoms are easy to catch if the person is aware of what heat exhaustion is. The symptoms of heat exhaustion typically consist of the following:

Moist, cool skin with goose bumps
Faintness or dizziness
Heavy sweating
Fatigue
Weak, rapid pulse
Nausea or vomiting
Muscle cramps
Headache
If the person suffering from heat exhaustion has a high body temperature above 103°F, call 911 immediately. This high temperature means that the person is past the stage of heat exhaustion and is suffering from a heat stroke, which can be life threatening.

Treatments

The first step to treating someone with heat exhaustion is to call a doctor or medical professional. As the CDC points out, heat exhaustion can sometimes lead to the much more severe heat stroke illness, which is considered a medical emergency. It is important to have a medical professional determine whether or not the victim of heat exhaustion is in danger of developing heat stroke.

Once a doctor determines that the person is not developing heat stroke and is instead suffering from heat exhaustion, then move the person to a cooler location. This can be into an air-conditioned building or simply into the shade. Once there, apply cool, wet cloths to the person’s body and have them sip water. If vomiting occurs, seek medical attention immediately.

Heat exhaustion is easily preventable if you know the signs. Make sure to remember these warning signs of heat exhaustion as your family enjoys the summer weather. It can be a lifesaver.