[Here's my MadMariner feature from two weeks ago. —Tim]
When I wrote my roundup of man-overboard alarms for MadMariner last spring, it became obvious which system fit my particular requirements best. I operate a small powerboat, inshore, often alone or with young children aboard. The most problematic overboard scenario I need to prepare for is the one in which I fall in the water and the boat keeps going without me, with nobody aboard to stop it.
The most immediate need, in this scenario, is to stop the boat. Luckily, this can be accomplished automatically with some of the overboard alarms I surveyed, including Maritech’s Virtual Lifeline.
In operation, it’s quite simple: When a crewmember wearing one of the small sensor/transmitters falls into the water, the Virtual Lifeline immediately sounds an alarm and stops the boat. If the remaining crew determine that they need to restart the engine to recover the victim, they press the “Rescue Mode On” button and restart the engine in the normal way. If not, the boat just bobs around where it stopped, drifting slowly down-current or down-wind.
This is the scenario I envision during my solo or short-handed outings in Puget Sound. Assuming I’m still conscious, I ought to be able to swim toward the boat and climb aboard. I’ve already tested three different methods of getting myself aboard without assistance, so I have a good idea what’s involved.
If I’m especially unlucky, and I’m unable to get myself back to the boat, at least the boat is in my immediate vicinity for the first few minutes, giving rescuers a snowball’s chance of locating me.
I like the Virtual Lifeline product for several reasons, some of which I explored in an earlier Navagear post. I like the fact that once installed, it requires almost no attention to operate. You don’t need to remember to turn the base unit on, or turn it off. Nor do you have to remember to turn the small sensor/transmitter units on or off. Other than the initial installation and periodic system checks, no additional action is needed.
Just don your PFD as usual and run the boat as usual; the system is working, ready to kill the engine if a sensor-equipped crewmember falls into the water. It requires about as much attention as a fire extinguisher, and I like that.
All equipment designers, but especially designers of emergency equipment intended for use in stressful, confusing circumstances, should strive to minimize the additional cognitive task burdens their systems impose upon users. But let’s set aside, for the time being, my ponderings on optimal ergonomic excellence. Today, I want to focus on installation issues.
Installation was my major concern with this system, you see. The Virtual Lifeline is wired directly into the engine ignition system, and it works by actuating the already-present kill-switch circuit.
That sounds great, but it’s also a little bit intimidating. I mean, what if I screw something up…would my boat be disabled? It’s only electrical connections, so while I knew it could all be put right, I was still reluctant to start splicing into the ignition wiring.
I recently took delivery of the product, and today I’d like to describe how easy it is to install.
It turns out I needn’t have worried. Maritech included color-coded connectors of the appropriate type for my engine. All I had to do was unplug three wires from the back of my ignition switch…
…plug them into the matching Virtual Lifeline wires…
…and plug the Virtual Lifeline wires into the ignition switch.
Easy to accomplish. Easy to undo. No cutting, splicing, or permanent modifications to the engine control system required. Once I figured this out, I had no further reservations about the installation. It’s just a matter of mounting the antenna, figuring out where to mount the base unit, and routing the wires.
I decided to mount the antenna against one the aft lazarettes near the transom. It would probably be better if it were mounted higher, but I’m interested in testing it in this location this summer, when the weather’s a little warmer than today’s 35°F!
You might have to spend a bit of time and/or money to mount the antenna. I used some leftover scrap plastic material, a table saw, and a heat gun to fabricate my own L-shaped antenna bracket, which I mounted by drilling four tiny holes and lashing it with some stainless steel bailing wire. Even if I decide to mount it elsewhere, the permanent modifications (four tiny holes) are quite minor.
It should be noted that an enthusiastic fishing friend assures me that I will want to move the antenna “after you lose your first big fish by having this mount cut your line!” Point taken, Tom.
Once all the connections were made, it came time to test it. Ah, the moment of truth! I turned the engine ignition switch to the first stop; the point where the gauges light up and things beep briefly, letting you know the engine is ready to start. Lo and behold, the Virtual Lifeline beeped too! Then I started the engine, and everything appeared to be working fine. The buttons on the front of the Virtual Lifeline all seemed to behave the way they should. So far, so good.
Then the really fun part: time to dunk a sensor into some water. In freshwater, the engine stops the instant the sensor unit goes under water, with no delay at all. In saltwater, the engine stops the instant the sensor unit emerges from the water. This suggests that it will be important to attach the sensor in a location where it will pop up above the surface of the water, particularly for saltwater boaters. It wouldn’t do to attach it in a location that will remain submerged.
Currently, I’ve attached my sensors to the bottom of our Mustang automatic inflatable PFDs. In saltwater, the sensor might remain submerged until the PFD inflates. Could the boat run out of range in that time? It might make more sense to attach the sensor high up near the shoulders or neck. It needs to be on the outside of the PFD, because you want to ensure that it gets wet right away. Obviously, I’ll need to do some testing this summer.
My at-the-dock testing indicates that the Virtual Lifeline system works at some range, at least a hundred feet if the transmitter has a clear line-of-sight to the antenna. The Virtual Lifeline has a “Sensor Test” mode that allows you to test the functionality of the sensors and the entire system without
affecting engine operation. This should be done periodically. I use a permanent marker to apply numbers to the individual sensor units, and then just record the test results in the vessel log.
The biggest hassle is getting all the water out of the sensor units so you can get underway again! If even a little bit of water remains inside the sensor casing, it continues to transmit. My favorite solution to this problem is to tie the wet sensor to a length of light line and swing it around and around fast, “centrifuging” the water out of the unit. It looks a little silly at the dock, but it works!
This summer, I plan to conduct some extensive tests in fresh and saltwater, both with MOB dummies (throwable cushions, probably) and, perhaps, with real live subjects. Stay tuned!
