Blog April 2021

Here's a great article by Captain Bob Figular for the Mariners Learning System about the often misunderstood land breezes.

The opposite of a sea breeze is a land breeze. While sea breezes occur during the day, land breezes occur at night. Despite the difference in times at which the land breezes and sea breezes occur, the reason for the land breeze’s formation is the same as the sea breeze, just the role of the ocean and land is reversed.

Land breezes can occur when the land’s nighttime temperature is less than the sea surface temperature. They are most common during the fall and winter seasons when water temperatures are still fairly warm and nights are cool. However, unlike the sea breeze, the land breeze is usually weaker.

At night, the land temperature falls to below that of the ocean and becomes less dense. Therefore it begins to rise. The rising air creates a weak low-pressure area due to a decrease in air mass at the surface. As the air-cools, it begins to collect resulting in an increase in pressure, creating a “high”.

These differences in pressures over the water, both at the surface and aloft are greater than the differences in pressures over land at the same elevations over the water. Therefore, as the atmosphere seeks to reestablish equal pressure both onshore and offshore, two high-pressure to low pressure airflows develop; the onshore flow aloft and surface offshore flow, called the land breeze.

Land breezes are weaker than sea breezes but not because of the difference in heating. Daytime heating and nighttime cooling occur at about the same rate so the potential for the both land and sea breezes to be the same strength exist.

But at night the cooling ground inhibits vertical motion that, in turn, weakens the land breeze circulation, Nighttime cooling also produces a shallower change in temperature so land breeze circulation is shallower, and terrain, vegetation, and buildings inhibit the flow of air from land to water.

When lives are on the line – your boat is on fire or sinking rapidly with people on board or someone is in imminent danger of dying without immediate medical assistance – you want every available resource dispatched to your position.

A Mayday call will bring that kind of help. Not only will the U.S. Coast Guard respond but the Coast Guard may notify state and local search and rescue units in your vicinity and ask them to respond as well. The Coast Guard will also transmit an Urgent Marine Information Broadcast over marine-band VHF-FM radio Channel 16, notifying all vessels in the area of your emergency. In many cases a nearby Good Samaritan will be first on the scene to render assistance.

A Mayday – the term is derived from the French venez m'aider, meaning “Come. Help me” – should be transmitted if possible via marine-band VHF-FM radio Channel 16 or 2182 kHz MF/SSB. Emergencies can go from bad to worse in seconds so try to get as much information across in as little time as possible.
 International Maritime Organization protocols call for beginning the transmission with the word "Mayday" repeated three times, followed by the name and number of your vessel and its position. If you have a marine GPS, relate the latitudinal and longitudinal coordinates. If not, state your distance and magnetic or true bearing from the closest navigational landmark. If time allows, you can also relay your departure point, departure time and the speed at which you were traveling. All of these can help rescuers locate you.

• Sun damages not only your skin but also your eyes. Protect yourself all over.
• Skin cancer, including melanoma, doesn't necessarily occur in areas of your body where you've been exposed to the sun. It can occur in areas where you're seldom, if ever exposed. Check everywhere.
• Sun can cause tan and even burn just by reflecting from the water. You don't have to be directly out in it.
• Wind burn, while hardly as serious as sun burn (as far as we know) still can cause severe drying of the skin, causing discomfort and also promoting aging.
• I'm not a doctor. When you talk to your doctor, ask him for the latest advice on exposure to sun and wind and include those among the risk factors for you which he regularly considers.

Here's how NOT to prepare for the upcoming boating season.

Don't change your 4 stroke oil by emptying the old oil out that little hole that some manufacturers put in the aft end of the lower unit.

No matter how hard you try, you're going to spill it and then the EPA and the state environmental people and everyone else will criticize, castigate and penalize you for the transgression. Draw that oil out the dip stick hole even though it takes 20 times longer and you're probably going to knock over the bucket full of old oil anyway, regardless of its source. Now if you have one of those better designed motors that allow for oil extraction without spilling, you're in luck. But I'm not sure there are any

You are finally in the water, and looking forward to the season ahead. Don't forget to take a few steps to ensure success.

That more vessels sink at the dock while unattended than sink while underway and manned.  A common reason for this is when cockpit drains get clogged and the vessel takes on water from heavy rains or waves slapping over a low transom.  The added weight of this water lowers the vessel in the water until a through hull fitting or cut-out transom is forced under water.  Sea water then spills into the hull from the fitting or floods over the transom sinking the vessel. 

The average vessel's bilge pump system and battery capacity is not designed to deal with this amount of flooding, especially when unmanned.  The amount of flooding that occurs when a prop shaft falls out of a vessel, or from a lost sea cock, is substantial

The second most common source of sinking at the dock is snow and rain.  I had this happen to one of my clients’ boats because the self-bailing scuppers clogged from leaves. Rain followed, and followed, and followed—until they had a submarine. Also, many skippers believe that Bimini tops and canvas covers prevent water from entering the boat.  Wrong again. They slow it, but don’t stop it.  In the winter, stow them someplace dry and shrink wrap the boat.

So, more than 80 percent of the boats sink for two reasons—all of which adds up to checking the boat from time to time. Or paying the dock hand to, or your teenager who wants some extra spending money. But check it.

The best defense against a dock side sinking is to check on your vessel often, and ensure that cockpit drains are kept clear of debris.  In addition it is important to check and maintain all through hull fittings.  Plastic through hull fittings are notorious for degrading from UV exposure and snapping off at the slightest pressure.  If your plastic fittings leave a chalky residue when wiped with a finger, replace them now!  And take the opportunity to upgrade to a bronze fitting.  Hoses connected to above water through hull fittings should lead upwards if possible.  The higher the hose is lead above the waterline, the lower your vessel can be submerged without creating a back siphon. 

 Finally, if your vessel has a low transom (as found on many outboard powered vessels) be sure to dock it with the bow of the vessel pointing to any exposed stretch of water.  That way, storm waves will break on the bow rather than over the transom.

Wash Your Boat

I get asked this more than you think I should.

The first and simplest task in caring for your boat is to wash it regularly. If you boat in saltwater, rinse your boat thoroughly with fresh water after every outing to remove salt residue. Salt will not only corrode metal, fasteners and other hardware, left too long on your gelcoat, It can mar that as well. Use a long-handle, soft-bristle boat brush and some quality soap. Marine boatwash is best and is formulated for gelcoat. Car wash soap is next best and some boaters use laundry soap in a pinch.

If you don’t go out, and just sit in the marina for a week, wash the boat. If you boat in fresh water, wash the boat. General rule of thumb, every time you go out, wash your boat. If you don’t go out, wash the boat at least once a week.

The relationship between the wind and the waves is very important to boat to skippers. So important  that a completely new classification system was designed as a guideline incorporating both wind speed and the wave conditions most readily found at those speeds. This system, called the Beaufort Scale, was developed in 1805 by Admiral Sir Francis Beaufort of the British Navy. It is a guideline for what can be expected in certain conditions and a weather classification system. It assumes open ocean conditions with unlimited fetch.

Aside from just wind speed, temperature is also a factor in creating waves. Warm air (which rises) moving over water has a less acute angle of attack on the surface than does cool air (which sinks). A cold front moving across open water will create much steeper waves and hence create breakers sooner than a warm front moving at the same speed.

Also, a change in wind direction over existing waves can create confusion and hence larger waves. If a wind has been blowing northeast over an open body of water for three days and suddenly switches to northwest over that same body of water, new wavelettes will form within the existing system of waves. The energy of both systems will multiply to create larger waves.

When a wave system meets a current flow one of two things can happen. If the wind and current are both going the same direction, it tends to smooth out the waves, creating long swells. If the current and wind are moving in contradicting directions, it will create much steeper and more aggressive waves.

MAKING SENSE OF THIS

So, what does all this mean? Why is it important to know how waves are made? Well... You can determine several things from waves.

One of the things you can tell based on waves, is boat speed. This assumes that your vessel is a displacement ship, like a keelboat, and not a planing one like a speedboat. When sailing a displacement vessel, the boat is constantly displacing a large chunk of water as it moves along. The heavier the boat, the deeper the trough it carves through the water. Now, along with the physics of waves we discussed above, we can add that the faster a wave travels, the longer it is. As a boat's speed increases, the number of waves that it pulls along the hull decreases until the boat is actually trapped between the crest and trough of a single wave that it has created itself moving through the water.

When there's  a fire on board it gets bad quickly. Burn Tests reveal that in each fire, you'd have three or four minutes — to make a VHF radio mayday call, locate and use extinguishers, don life jackets, and prepare to abandon ship — before likely being forced overboard.

DSC

Having a working VHF with digital selective calling is critical. DSC messages provide coordinates, so anyone aboard can summon help and give rescuers your location by pressing the radio's red distress button. A waterproof handheld VHF with DSC is a smart idea as well, because in the event of a fire, an installed VHF will probably lose its power source quickly or be inaccessible.

Fire Drill

Do your guests know how to use the radio? The location of the fire extinguishers? Do they wear or keep life jackets close by? Do they know how to shut off the electrical system quickly? A five-minute guest briefing improves fire safety.

Water Drill

Beyond flotation and waterproof handheld VHFs, personal locator beacons, flares, and other signaling tools provide a lifeline from the water.

Fire Extinguishers

How many do you carry? Are they accessible in seconds? Are they rated ABC for all fires? Having several ABC tri-class extinguishers that go beyond the minimum U.S. Coast Guard requirements could save you and your boat.

Built-In Support

An engine-compartment fire-suppression system or, at minimum, an installed engine fire port into which you can discharge fire extinguishers can both contribute to the quick extinguishing of a fire, or at least buy you time in your fight against an engine-room fire.

PASS

Follow these four steps when using a fire extinguishers: Pull the safety pin. Aim the extinguisher at the base of the fire. Squeeze the handle. Sweep the hose from side to side while discharging.

Life Jackets

Many boaters bury them among the gear, then waste precious time locating them in an emergency. Regulations say that if jackets are not worn on board, they must be readily accessible.

Exit Route

Can you get out of the boat if the exit is blocked by fire? Carpet, headliner, cushions, curtains, and other flammables ignite when introduced to an open flame.

The Power Of Prevention

Are your electrical and fuel systems maintained to American Boat & Yacht Council (ABYC.org) standards? Electrical faults are the No. 1 cause of boat fires. What's the condition of your fuel lines? If they're 10 years old or emit a gas smell from a rag rubbed down their length, replace them.

Refueling

How many minutes should you wait to start the engine after filling up at the fuel dock? Answer: At least four, with the blower on and windows and doors/hatches open for the entire time. End the four-minute period with a sniff test.