Boy, you all are in my wheelhouse now! I singlehand a LOT (in many different boats) in some of Alaska's most remote and challenging waters. I regularly make 100 mile runs up and down the Copper River solo (as far as I know, I'm the only person who does this), and I work out in Prince William Sound and the Gulf of Alaska, and do a lot of my work dropping off or picking up field crews, so I'm usually single handed on at least one leg of any given trip.
I have to say that you guys are ahead of most. This is a very safety conscious crowd. I would expect nothing less from a group so dedicated to such a practical boat!
I actually don't have a ton to add that wasn't covered already, but wanted to reinforce what a few others have said, maybe in a slightly different way, and provide some of my experiences.
First, aside from all the prep (weather, fuel, proper gear, float plan, etc) developing a good situational awareness is critical, and something a LOT of boaters think they have, but they do not. One of the things that a passenger does that is rarely considered in single hand discussions is point things out that are interesting. Sometimes these things are important to the boat's operation. So, developing the discipline to maintain 360 degrees of lookout, all the time (not just in front of you), and then the ability to judge whether or not something is a big deal (comes with experience), and if you aren't ABSOLUTELY SURE something is ok, ERROR ON THE SIDE OF CAUTION. Situational awareness only goes so far. You can perceive a challenge perfectly, but situational awareness is far more than that, it means perceiving the problem, evaluating it, and deciding a course of action based not only on the immediate problem, but what will happen two, three, four or fifteen steps past that problem. An overly simplified example is a large beam wave heading toward you that you see and decided to steer into (probably smart) but then noticing that that course correction would bring you too close to a hazard, so you do something else like put the wave to your stern and ride in front, then turn into it when it's clear. That's situational awareness, and it needs to be developed, and can be developed by applying it to all the decisions you make, even when everything is going really well and you are making easy decisions in the captains chair. Just challenge yourself to think about these easy decisions three or four steps beyond. Then when you need to, it will be second nature!
Second, get some wilderness medical training. Taking your standard red cross first aid/cpr course is great, but wilderness medicine is different. The technical MEDICAL definition of wilderness is being one hour or more from definitive medical care (i.e. a real hospital). So, even if you are in New York harbor or cruising a mile from downtown seattle, YOU ARE IN A WILDERNESS CONTEXT medically speaking. Get some training on how to handle it. Wilderness First Aid is a 2 day course that every boater should take. It is a whirlwind though, and many may get a LOT more out of Advanced Wildnerness First Aid, which is a 4 day course, and paced a lot more reasonably. The ultimate would be to get trained as a Wilderness First Responder, which is a two week course, so really only practical for professionals or people with a lot of extra time. Also, learn how to throw a stitch. If you can get it, put some sutures in your med kit. It isn't difficult to do and it could be a lifesaver.
Third (maybe most importantly) get intimately familiar with your boat's response to control inputs. How many people know how many rotations their steering wheel is from stop to stop? How many people can hop onto any boat tied to a dock and center the wheel without moving anywhere? How many know exactly how their boat will respond when, for example, you turn the wheel 2 full revolutions to starboard at 3800 rpm? Most everyone drives a boat like a car (meaning that you end a steering input once the vessel has reached the desired vector when you should be bringing the wheel to center as you approach that vector) which turns the same at 2 mph as it does at 60, for the same steering input. How many of you keep track of the wheel turning in terms of revolutions from center, and know how many revolutions your wheel is from center at all times, such that you can correct back to center without the movement of the boat? If you can do this, you will stop oversteering (save gas!) and you will operate your boat much more safely. Most boaters, even the very very experienced steer WRONG, and oversteer constantly as part of their "normal" operation. Thus as they come to the direction they desire they steer past it and then have to correct and steer the boat in the opposite direction to stop the turn. I know people on here pay attention to their tachometers, so I won't go into that lecture, but steering a boat like a car is by far the most common issue that I correct. Having this discipline become second nature will enhance your ability to control your boat, and can almost be like having an extra sense at your disposal once you are fluent. When things get nasty, it gives you one less thing to think about because knowing your wheel/rudder position will become automatic, and become separate from the direction the boat is moving, which aren't always the same!!!
Fourth, I'd like to discuss EPIRB, PLB, and Communicators (I use all of them regularly, and for different purposes). SPOT and InReach (communicators) are awesome for communicating that you are okay. Not as good at summoning help because they do not have a direct line to SAR, which a PLB or EPIRB does have. InReach does allow you two way communication, so you can participate a bit more in summoning help, but messages move slowly and in the midst of a crisis, may be more of a distraction than help. An EPIRB is ideal, but usually too large to carry on you at all times. a PLB is a smaller version (yes, there are mini EPIRBS too) with the same general idea (register straight to NOAA, activation of the device goes straight to SAR). You want to have at least a PLB on your person at all times, separate from the EPRIB on your boat.
There are two technologies used to get SAR to you once one of these device shave been activated. The devices emit a radio frequency (406mhz, do NOT get one operating at 121.5mhz!! Those are old and not monitored by satellite anymore!) that can display your position when polar orbiting satellites measure the doppler shift of the frequency as they pass over. This can also be monitored by handheld receivers that detect the signal's direction. All of these devices do this. EPIRBS, and the better PLBs also encode your GPS coordinates in their radio signal and deliver that info to SAR. This is a pretty huge advantage to give rescuers, HOWEVER, I have been on land, awaiting helo evac, with my exact lat/long communicated to the helo, and a signal mirror, and it still took them ten minutes of flying around to find me... the point is that you need to give SAR every advantage, and even if you do, they still will have a tough time looking for you. Someone posted that these devices take the "S" out of "SAR." They do not. They just help, a LOT, but there is still a lot of searching to do.
Fifth, when I'm alone, I pee into the splashwell. Kind of gross, but it cleans easily. The stats on drowning deaths from boats where the victims are found with their pants down are no joke.
Finally, If I'm working alone on the boat, especially if lines are in the water such that fouling my prop is a concern, and conditions aren't ideal, one thing I'll do is use my kicker as my primary power/steering. This way I'm controlling the boat from the cockpit where I'm working, and if the prop gets fouled I have my big engine to get home on. I've learned this the hard way and nearly had bad days turn into last days because I fouled my main prop in a bad spot.
Some ideas I've had but never tried the effectiveness of (thank goodness!)
1. If you have AP you might keep a remote control on you, and you could just steer the boat back to you if you can get to the remote before the boat is out of range;
2. if you have a remote windlass, perhaps you can deploy your anchor in time to stop the boat's drift
3. There are some gizmos out there now that have individuals wear a fob, and if anyone goes overboard, it automatically alerts/alarms and discovers a distance and bearing to the MOB (e.g.
http://www.manoverboardsystems.com). This is really cool technology, and has saved lives, but requires at least one human to remain on board. I see no technological reason why that tech can't be integrated into an AP system such that the boat returns to the MOB, stops a small distance away, and maintains position. I can see that if there is a current or wind that the boat could stop downwind/current from the MOB, making it an energy sapping and likely futile chase, but there are certainly ways around that, like returning a boat to within remote control range (and integrate the MOB fob and the AP remote). I would spend some serious $$ on that type of technology, and it would pay for itself in my workplace by allowing me more discretion in sending staff out solo (I am the only one who is allowed to be without a buddy, but I usually take a very good dog with me who has saved my bacon a few times, but that's a different story!).
