[PSUBS-MAILIST] Sonar, Sirens, Protectants, and Pumps.

Almost ten years ago, I put the NAUTILUS MINISUB into storage and went looking for a new home base, finally settling in Hawaii. To protect the ballast tanks, I introduced a liquid preservative which was applied by first flooding the tanks with water, draining off a bit, pouring the protectant into the top main vent valve, and then emptying the tanks through their bottom sump drains. This process was recommended by the protectant's manufacturer, and the idea was that the substance would coat the tank interiors with a "non-toxic waxy film" as the water level fell. (The stuff was designed for use in water tanks.)

Yesterday, I flushed all four tanks, and found them virtually free of corrosion, and there was evidence that the "waxy film" was still there. A pressurized hydro test disclosed not so much as a pinhole. Pretty satisfactory protection after that much time, I think.

Problem is, I'd like to get some more; nobody over here has anything like it; and I can't remember what the name of this stuff was. I bought it from Orchard Supply Hardware in California; and have sent them an inquiry via email; but so far no reply. IF ANYBODY KNOWS THE NAME OF THIS OR A SIMILAR PRODUCT, I'D APPRECIATE HEARING ABOUT IT.

BOATERSWORLD has a wide variety of items that might be of interest to psub owner / operators. For example, I found a new fishfinder (my old one apparently gave up the ghost over the years) at a reasonable price, and with more features than I started out with. The new one I'm getting also has a readout for water temperature and boat speed.

(BTW: a while ago, somebody at PSUBS questioned how well a fishfinder might work in my NAUTILUS while underway. Well, the old one did fine at the slow speeds we worked at; and even with the new 36VDC MK-101# thruster, I don't expect to reach "collision speed" as depicted in the movie. Still, the fishfinders I'm seeing now are rated for use in boats traveling up to 70 mph; so to answer that earlier question: I think they'll be adequate for use in a sub. And some of them even include GPS: probably impractical for a limited-range boat like mine, but one never knows; and for those of you with the autonomous variety who might actually be using it to go someplace, they might be worth looking into.) My new EAGLE unit lists for $149, and BOATERSWORLD has it for $99 with free shipping. So I think their prices are reasonable, too.

About BOESHIELD T-9: I just came across it, and don't know much about it other than it was developed by the BOEING Aircraft Company, and (like that other stuff I used) it protects by leaving a "clean waxy film". But T-9 sounds pretty good so far. They've got a website at boeshield.com., or type BOESHIELD into your browser. The stuff aint cheap, though ($80 per gallon); but for me, it's worth it to keep the integral ballast tanks on my sub from rusting away. It also comes in spray cans (for a lot less money) too; and can be used to protect a wide range of systems and components you might have on your sub besides ballast tanks. Those of you interested in protecting your boats might want to check it out.

ALSO: during the initial proving tests of my sub back in '91, one of the first problems we had to overcome was COMMUNICATIONS between the pilot and support crew, especially in an emergency. (The first time we submerged on ballast alone: a rush on the ramp, too much time spent answering spectator questions, and a subsequently inadequate pre-float check resulted in a misaligned hatch seal and an incorrectly set ballast valve which created a minor incident that had me shouting for help.) Now, I've installed a PA system to transmit voice (mine), music (the sound track from 20,000 LEAGUES, of course!), and / or sound effects (a jet turbine "whine" to simulate the sound of the NAUTILUS on the attack) to the outside world; and we now have an underwater radio-telephone enabling voice comm with the dive crew underwater (thanks again, Phil). HOWEVER: I came across something at RADIO SHACK which was cheap and seemed like a good thing, so I bought one, and I'll pass it on to those who might be interested.

The "gadget" is a 12VDC PIEZO SIREN: measures about 1" X 1.5" X .5", and "yelps" at 102db while drawing only 150mA. The device uses a Piezo disc and small circuit board in a plastic box; and it will work underwater. (I submerged it overnight, and it still worked in the morning, though it kind of "gargled" and lost a little volume). Nonetheless, my plan is to enclose it in a small PVC housing mounted outside the p-hull in the free-flooding area under my sub's afterdeck. The idea is: if I get into trouble, a flick of the switch and every member of the support crew knows about it "right now". One thing I learned the last time: response time in an emergency is critical. Seconds count. On the surface or underwater, this siren could be an advantage. Plus, it's only $5.00. Cheap insurance. The RS part number is 273-079.

Another thing: I've decided to install a BILGE PUMP. I use packing glands for my control shaft-outs, and in the past, they have leaked some after several dives. The problem is (especially with the rudder-shaft gland way back in the tailcone) it's hard to know when such leakage begins until there's so much water in the boat that you can see it; and (in my boat) squirming all the way back there (over the battery pack and air tank) with a wrench to tighten the gland (while afloat) is a bit of a bee-itch, if you know what I mean.

So, the RULE company makes a line of pumps that are 12VDC, reasonably priced, and there are manual and automatically-operated variants. An automatic bilge pump on board, (maybe incorporated with the siren mentioned above) could be a handy thing to have. They aren't very big (space consuming) at all, either. RULE has their own website, or type BULGE PUMP into your browser; their pumps show up a lot on eBay, too.