What is monitored? Bilge water level - using a bilge-water alarm sensor. The simplest form is a float switch which can send a signal to a central alarm system.
Smoke and carbon monoxide - detectors can send a signal to the alarm control box.
Gas leak - using a gas detector with terminals for a gas cut off solenoid valve.
Intruder alarms - such as door switches and pressure mats.
Dinghy and outboard removal - using a continuity cable.
Geographical position - using GPS. A 'geo-fence' is created around the boat's position, when the boat leaves this area an alarm is triggered.
A webcam - can be linked to most systems so you can actually see the boat for yourself.
What information is transmitted? In marina based systems, a warning is displayed on the control panel and a member of staff will check the boat's security.
A GSM based (non GPS) system will send a message to the owner to alert them of any problem.
A GPS system will send a text message. With a service contract, the service provider will alert the police if there has been a theft. A GPS system can track the boat anywhere and will warn by text or email.
Doing it yourself Professionally installed systems are less likely to result in false alarms and unnecessary travelling, but it is possible to do it yourself.
You can buy sensor components individually and wire them together with a control box. The warning signal can then be transmitted to a GSM modem and the signal is sent to a mobile phone network of your choice. Alternatively, buy a dedicated alarm kit, complete with sensors, and send the signal to a pay as you go GSM modem.
Another option is to buy and fit a full boat kit, including GSM modem and GPS receiver or with a satellite modem and GPS receiver.
Wired or wireless? The easiest way to set up a system is wirelessly - there is no need to run cables from each detector to the control unit. However, each detector needs its own battery for its wireless transmitter and you may not be able to incorporate bilge water, smoke or gas detectors unless you can find wireless varieties.
With a low number of detectors required on a small boat, it is recommended to opt for a wired system.
Where to buy a kit? There are many companies which supply security equipment. If you make up your own system then your components may consist of:
Bilge water float switch Pressure pads Door contacts Heat detector
In conclusion A non-communicating system with an external alarm will just make a noise, annoy people and will probably be ignored. If your normal berth is in a marina, you can use their wireless security system if they provide one. This will only work in a marina with the same system, so you'll have no protection if you leave the boat elsewhere. Be sure to contact them and check for availability and pricing.
A system communicating via GSM phone link can send messages to one or more phone numbers. They may also be able to send email messages or even voice messages to your phone. They will work only when in range of your mobile service provider's network and will incur roaming charges if you go abroad. For long stays abroad you could use a local pay as you go SIM card. This can be a relatively cheap option with no monthly contract. Some of these can link your PC to a website where you can view a map showing the position of your boat.
