LIVING in a coastal city and being an offshore mariner makes me give more thought to disaster preparedness than some. For example, my boat has two of almost everything, including two VHF radios, one a handheld submersible; two bilge pumps; two manual fire extinguishers and one automatic one; a spare storm anchor; a second, never used, get home battery; and so on. Since Hurricane Katrina devastated New Orleans, I have been thinking a lot about how technology could be helpful in case my family were ever in the middle of such a disaster. Here are a few thoughts on the topic. If you ever have to evacuate quickly, what do you grab before you go out the door? Family photos, insurance papers, medical records, and the laptop computer are a few things that come to mind. Taking all these things would amount to carrying a cardboard box full of stuff--not very handy. Fortunately, there's a better plan, and it's an emergency USB flash memory drive you prepared in advance. A flash memory sometimes called a thumb drive, is a solid-state device and doesn't really contain a disk drive. Last May, Sandisk began selling waterproof USB flash memory drives in various sizes. Sandisk's plan at the time was to sell the waterproof units to resellers in the health-care industry and in the military. I was unable to find resellers of these units, but I believe they will probably be available soon. Until that time, you could always use a tough ziplock storage bag and a plain USB drive. By the way, if you ever have a valuable hard drive fail, don't immediately give up on salvaging the drive's contents. Several firms, such as www.drivesavers.com, are experts at repairing drives that have gotten wet, hot, and even crushed. The advice from DriveSavers for a wet drive is to turn off the computer immediately and place the drive in an airtight plastic bag as soon as possible. If water dries on drive surfaces, it can leave deposits that make recovery difficult. Recovery of drive contents is not cheap, but DriveSavers did offer a 20% discount to Katrina victims. If you are like me, you probably have several USB drives. To mark one of mine as the emergency I simply borrowed some red nail polish from my wife and painted its case. Then I filled the red unit with important files like my family finances spreadsheet with all of our account numbers. I now take the red drive with me everywhere. My drive has 256 MB of memory, which holds an amazing number of files. The optimum size is probably 512 MB, which is about the amount of information you can write to a recordable CD-ROM disk. One problem with such small devices is that they are easy to lose. I suggest attaching a tag of some sort to the drive with your name, address, and telephone number on it. Some people like to put the drives on a lanyard, but I find that cumbersome. Another backup technique is to use an online service such as www.backup.com. Backup. com encrypts and stores files securely. The company offers a variety of plans, from $4.95 a month for 256 MB to $99.95 a year for 500 MB. An even cheaper approach is to simply make it a habit to e-mail yourself important files. You can sign up for a free Gmail account from Google that comes with 2 GB of storage. Since I don't know where Google locates its servers, I would be a little anxious about relying on this approach. Most operations the size of Google use a network of highly distributed servers. It is likely that Google lost servers in the region devastated by Katrina. For serious backup, I use a small portable 60 GB, USB 2+ FireWire 800 disk drive. This is a very fast portable drive that spins at 7,200 rpm. Most portable drives are 5,000 rpm or less. Various newscasts following Katrina often reported that police, fire, and other rescue personnel lost all communications with one another. That is unfortunate because of the easy availability of portable satellite phones. Out of curiosity, I went to www. …