Entries Tagged 'Marine Electronics' ↓

Winter’s approaching and boating activities usually diminish during the colder months especially in the southern states. Many boat owners use the extra time to do repairs and upgrade equipment.

Although not usually at the top of our priorities we know we should check our safety equipment as the use by dates for some items always come around sooner than anticipated.

This year it will also be time to upgrade your EPIRB if you still have one of the old 121.5 Mhz types. From 1st February 2009, alerts from these beacons will no longer be received by the Cosaps-Sarsat satelite system. Aircraft that are fitted with 121.5 Mhz receivers will still pick up the signal if they are in the vicinity and have the receiver turned on.

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Are you considering buying a GPS plotter or a laptop for your onboard navigation?

Here are some of the pros and cons.

GPS Plotter Advantages

• Waterproof - A GPS plotter has been designed to operate in a marine environment and most units are sealed to protect them from damp salty environment with some level of waterproofing.

• Secure mounting options

• The screen is visible in bright light

• Software is more stable - Compared with common standard computer operating software

• Integrates with other marine electronics- Most GPS plotters will interface with compatible autopilot/sonar/radar/weather receivers etc

• Lower power consumption compared to a laptop

• Cheaper- Arguable, but a cheaper plotter is around $600, a second hand laptop is about the same, but which will last longer in a marine environment?

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In the last few years the development of LED light globes has progressed significantly. They are now readily available in all common 12v light fittings at a realistic price. Many new cars are using LEDs for their front and rear lights and many traffic lights utilise LEDs.
This is great news for boat owners as the old energy inefficient incandescent bulbs can be replaced with long lasting low power LEDs.

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The lead acid battery has been around virtually unchanged for over 100 years. There are 2 main types with 2 different purposes.

One is what we will call a starter battery. Every car and every boat with an engine has one. It is designed to produce a lot of current for a brief period to power the engine starter motor. As a consequence it must be recharged slowly to get it back to full charge. Starter batteries have a lot of thin lead plates with a lot of surface area to provide the big burst of energy required by the starter motor. The thin lead plates are easily damaged by a high charging current.

The other kind of battery, which we will call a traction battery, is the type used in electric golf buggies amongst other things. These batteries are designed to discharge slowly over a period of time and can be discharged more deeply. They can be recharged more quickly as the plates are more robust. This is a true deep cycle battery. These batteries have thick lead plates as the energy is dissipated more slowly. Consequently they can take a higher recharging current.

There are some hybrid batteries available which are sometimes sold as “deep cycle” batteries. In essence these are starter batteries with slightly thicker plates to improve their deep cycle efficiency slightly. It is important to check exactly what you are buying so that you get the type of battery you require.

Which battery should you use?

Some of this boils down to the cost. A starter battery may cost $125. An equivalent hybrid would be around $240 and a traction battery $380 for similar sized batteries. The traction batteries require a different charging system incurring more expense.

On a boat ideally we need both types of battery and if we are going on a round the world cruise it makes sense to have a starter battery and a house bank of traction batteries with appropriate charging systems. Boats used occasionally on the weekend can opt for the cheapness and simplicity of ordinary 12v starter batteries. For a boat which is occasionally used for longer periods then either starter batteries or the hybrid type for the house battery would be suitable as they can use the same recharging system.

DSC or Digital Selective Calling is a paging system that enables DSC equipped marine radios to send a signal which is picked up by other DSC equipped radios that are in range. The DSC unit then alerts the radio operator, usually with audible and visual alarms. Once contact is established, communications are continued manually by voice on another channel.

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