In 'Mission: Impossible,' Tom Cruise pulls out all the stops in his attempt to break into the CIA. While it's unlikely that anyone will put forth a similar Herculean effort toward breaking into your boat, its security (and the 'stuff' that resides within) is not something to be taken for granted. By taking a few simple precautions, you'll be able to protect yourself against boat theft.

One thing to keep in mind about boat security is that the favorite target of thieves are boats 20 feet long and under (including PWCs). According to the National Insurance Crime Bureau (www.nicb.org), this size boat represents 90 percent of the over 27,000 annual boat thefts. The most popular times for thefts are before daybreak and sunset, Mondays, or the 'day back' after holiday weekends and off-season when your boat is less visited or stored. Note that the majority of boats stolen are stolen while on land ... doh!

As in any kind of theft, there are three criteria that will cause thieves to look elsewhere: time, noise and visibility. While any cop will tell you that thieves and criminals aren't the brightest bulbs in the pack, they're generally far from dumb when it comes to their occupation. A smart thief will factor in the time it's going to take to boost something, so you want to make whatever it is time consuming to remove. The more noise they'll have to make while trying to remove something, the bigger your advantage. Last is visibility: People involved in illegal behavior tend to do so where the light shines the least.

SIMPLE STUFF
There are some simple things you can do to prevent your boat from falling victim to thieves, before you consider alarms. For starters, if you trailer your boat, have some sort of locking mechanism on the wheel or hitch bar. One of the simplest is a locking device that's inserted into the coupler lock (the thingee you can never open or close that locks the trailer to the ball). They retail online for under $30. Another more expensive, but nobody's-gonna-get-your-trailer system is called the Trimax Umax 100. It retails for around $60 and attaches to your trailer coupler, preventing any hook up. Both ' and a lot of other style locks -' are made by a Pennsylvania company called Trimax (303/796-8500, www.trimaxlocks.com).

A company called DuraSafe (800/544-5615, www.durasafe-usa.com) manufactures one that locks your trailer coupler to your trailer hitch (like when you're parked in a motel lot ' the most likely place from which to have a boat stolen, according to the NICB). This unit, the Trailer Guardian Universal Coupler Lock, retails for around $50.

Another method is to simply chain your tire to the trailer's frame. This is best done with a device like a Hammerlock chain, said to be impervious to bolt cutters, saws, etc., and a quality, case-hardened lock. This flat link chain goes for around $11.50 a foot, and a good lock costs around $75. Check Southern Charm, a Florida mail order/Internet boating and fishing outfit (800/745-0765, www.boaterscatalog.com). Other trailer locks look like the metal 'boots' parking enforcement people place on illegally parked cars. These can run up to $200, but work exceptionally well.

DuraSafe also makes a line of locks specifically for bracket-mounted electronics. One of the knobs attaching your unit to the bracket is replaced by a DuraSafe locking knob ' a simple solution for electronics for under $20. Each manufacturer has different screw patterns, so you'll need to know what brand you have.

For those with outboard engines, it's a good idea to super fasten that motor to your boat. Q Lok (508/966-9488, www.qlok-usa.com) makes a nifty motor lock that covers the bolts locking your engine to your transom. It also has a part that covers the head of the bolt from the inside on the boat side. Figure between $70 and $110 depending on motor size; the inside bolt cover will cost you about another $30.

McGard (716/662-8980, www.mcgard.com) makes locking bolts that work on the same principal as locks used to keep those $10,000 car wheels that look like they're spinning when they're not moving and actually cost two grand and more each. Figure around $30, and these are also a smart bet for your outdrive which, while not costing as much as an outboard, will still cost a bundle if boosted. Similar systems exist for preventing prop theft.

One simple way of securing cabin doors is called the Powerbolt 1000 by lock maker Kwikset (800/327-LOCK, www.kwikset.com). A deadbolt lock designed for homes, it runs on four AA batteries, has 390,000 different owner-set security codes, a secondary one-time code ability for allowing temporary access, and sounds an alarm if the code is tried unsuccessfully three times. Priced under $100, it will certainly add a bit of panache to your boat.

ALARM SYSTEMS
But what about when your boat is in the water? Nowadays, there are a plethora of companies dedicated to just that problem. You can go from simple self-installed systems to high-tech monitored systems that will call you or a security company no matter what happens to your boat while you're not on it.

One key fact to be aware of is whether or not the unit is simply a car or home alarm in a new suit of clothes. All (yes, all) car alarms and almost all home alarms have their circuitry manufactured in China, so that's one way to figure what type alarm is used. Secondly, hard-wired is the only way to go; wireless doesn't seem to be at the stage of development where it can be thoroughly relied on in the marine environment.

Naturally, the hard part in doing it yourself is wiring the alarm system, so this may be beyond the skill level of many, and a good reason to have a professional install your alarm. There's a decent list of security alarm companies at www.charternet.com).

Most systems operate in the same general manner. First off, there are sensors that detect movement, doors or windows opening, weight on deck mats, ladders or steps and even the aforementioned 'Mission: Impossible' movement ' triggering photoelectric beams. But the key is a command and control unit that does all the work of arming, disarming, transmitting, setting off alarms and more; the brain of the system, so to speak. A system can run anywhere from around $300 for one or two sensors, a control unit, and an alarm/loudhailer, to $2,000 for something that monitors your bilge via chartplotter-connected video, has spray sensors to detect through-hull leaks, a GPS tracking system, a notification system (that will call your cell, home phone, law enforcement, fax you and send you e-mail) that a breach or high-water problem has occurred, and more. Some systems have the ability to shut engines down if the craft moves out of a specific GPS-designated area, while others will monitor the status of virtually every system on board your craft and display the info on your home PC (SeaCurity Systems, 631/226-1616, www.seacurity-systems.com).

Marine Marketing (727/864-9350, www.dinghyalarm.com) covers a range of marine scenarios with their products. For trailer boaters, the $200 Tilt Alarm, which can be affixed to trailers, stores the 'tilt' of the trailer as a benchmark and triggers an alarm if a 10-degree movement off the original tilt is detected. The company also offers an alarm system that places sensors on your canvas snaps. Pop a snap and a 107-decibel alarm goes off; it retails for $199.

The same outfit also makes a voice alarm system (www.voicealarm.com), an entry system (www.shipsecure.com) and a bilge monitor alarm system (www.bilgemonitor.com). These U.S.-made units are incredibly sophisticated and relatively inexpensive considering everything they can do.

A bilge monitor is a good add-on to any security system, but Marine Marketing's unit takes it one step further, allowing you to monitor your engine room while underway via a separate screen or at your chart plotter screen. The system also offers spray sensors, something the company developed, to give you a heads up on water entry. The company's Voice Alarm unit offers a command module that will announce over an extraordinarily loud hailer (107 decibels) virtually anything you want. There are also options that activate up to eight telephone numbers when an alarm sensor is breached, or will switch on a video camera, etc.

Many outfits offer magnetic sensors that, when the magnets are pulled apart, break an electrical circuit and trigger the alarm system, typically used on doors and hatches. Some offer the aforementioned photoelectric beams that can cover a wide area (Flagship Marine Security, 516/487-9650, www.boatalarm.com).

And then you have pressure-sensitive 'welcome mats' rigged to the command and control module (Marine Guard Network, 866/286-1308, www.marineguard.net). Some types can be epoxied under the deck and will pick up flex in the deck over a surprisingly wide area. Others are actual mats wired to do the same. Some can be rigged so the downward pressure exerted by someone climbing the ladder to your wheelhouse will trigger the alarm.

Lastly ' and along with the high-water alarms, probably the smartest investment ' are sensors that connect in-line to your instruments. Pull the instrument out of its location or bracket, and it opens a circuit triggering your alarm system.

APPROACH POINTS
Setting up any system requires some thought, especially if you're doing it yourself. Those with a military background or some interest or experience in booby traps, minefields and setting up defensive perimeters, and fire and kill zones will appreciate this part of the exercise: It's all about the avenues
of approach.

You must ask yourself: What are the most likely sections of your boat wherein erstwhile future guests of the state will attempt to gain access? Think about the different ways you board, and those are the locations thieves will board. Don't discount boarding from the waterside where appropriate. All are sites where you'll want to place your sensors or system activation hardware.

To sum it up for the DIYer: Determine what system you want and what type of sensors you'll need. Then ' before purchasing ' see whether it's possible to do the wiring yourself, where the sensors will be located, where the command module will be located and where your alarm/siren/call sending unit/etc. will go. Then it's back to the dealer or manufacturer for an installation manual (some manuals are offered online). Read the manual carefully ' as if you're putting together something for your kid the night before Christmas ' and decide whether your DIY self is up to the task.

Regardless, when you're confronted with a price for a system whether installed by you or by a security company, don't balk ' just remember how much you've invested in that good ole' hole in the water, and sign on the dotted line.