Thursday, January 26, 2012

That Helpless Feeling When Draft Exceeds Depth

  On a river, channel markers are nice guides, and charts have their use, but if channel markers get moved by wind or current, and the fluctuation of river levels make charts questionable, the depth finder may be a captain's only friend.

A haul out usually is mandatory after an incident involving the running gear hitting the bottom.

  Shortly after acquiring our current version of Swing Set we were headed to one of the larger boating parties of the summer in a slough behind Two Branch Island on the Mississippi, just upstream from the Golden Eagle ferry on the Alton Pool. Being July, the water was low; charts indicated no navigable depth approaching the sand beach where everyone was to raft up, so a few of the organizers of the annual Jamaica Daze party promised to mark a channel for the boaters to follow. 
  The morning of the party came; Rosie and I headed upriver early as we knew there would be  hundreds of boats and party goers making their way in that direction later in the day. As we approached the downriver end of Two Branch, we could see the early birds already gathered at the beach and the channel markers were also in place.
  The channel markers were made of balloons put in place the previous night, anchored by rocks. The wind was blowing pretty good and little did I know that the wind had blown the balloons off course. I was making way at idle speed through the markers at a minimum depth for Swing Set, which is roughly 3.5 feet when the depth finder starting complaining and we came to a sudden stop. I had enough presence of mind to shut down both engines to survey the situation, a first response that I have followed religiously since.
  Sometimes on a river with a current, a shallow water level can be overcome simply by shutting down and allowing the water flow to push the vessel back into deeper water, but such was not our luck on this day. I slipped off the boat from the swim platform to find myself in thigh deep water, not deep enough to float our boat free from the grip of the sandy bottom.
  Now, Swing Set weighs in at 11 tons dry. Add a few thousand pounds of fuel, water, groceries, and a fair amount of beer for the weekend and the prospect of me pushing her off on my own was a dim one. However, in the nearly twenty years since our episode in the Keys, when we ran aground in our 24 foot Formula, I hadn't killed all of the brain cells that recalled how I extracted us from that similar situation.
  I walked upstream to the bow of the boat, which was still floating, as we were only stuck due to the rudders being in the hard sand. Not bothering to send Rosie to the bow to shift some weight there, I pushed with my back to the hull and got Swing Set to turn around with the bow faced into the direction I wanted to go, which was downstream. We had slipped some and I was in slightly deeper water, so I climbed back in and fired up the Caterpillars and slipped the starboard engine in gear, only to get a THUNK in response, so I quickly got her back in neutral and shut down the engines.
  Realizing that I now had the current and the wind pushing from the stern, I climbed back into the water and attempted the seemingly impossible task of moving an insurmountable weight with muscle power. Again, I realize now why my back is a mess.
  Inch by inch, Swing Set found deeper water until I was able to climb back into the boat and pilot her out of our sticky situation.
  Two more times I got us into similar situations; once more at the same location behind Two Branch Island and another time as I approached what has become one of our favorite anchorages below Lumpy Island.  At issue with navigation on most rivers is that even in familiar territory the river bottom changes from season to season. During the winter layup, the floods and currents will shift the sand and mud around in places where once was navigable, and then becomes a spot to avoid.
  Our second soft grounding that occurred behind Two Branch Island happened when I had help on board, but every time we were able to shove ourselves off of one sandbar, we promptly floated onto another one, driven by wind and current along an undulating river bottom. We finally had to be pulled off with some friends in another vessel, for which we will remain forever grateful to Carl and Mary Tiemann, River Rats to the core.
 During another soft grounding behind Lumpy Island, I was so mad at myself for getting us into the predicament, I refused aid from a passerby on a personal watercraft and was determined to get us out of our pickle without help, and I was able to.
  That feeling in the pit of your stomach when boat meets bottom is not a pleasant one, but I have one more incident to tell about, and that was in October of 2007.
  Rosie and I were enjoying a late season one week vacation aboard Swing Set and we found ourselves alone on the river during the week on a very cold and blustery day. We had left Alton Marina from an overnight stay and were heading up river when I decided to leave the main channel and take a tour of Piasa Harbor, a place we had never visited by water.
  I had heard that the channel into Piasa was a shallow one, but also knew that there had to be a navigable route because other vessels of our size were berthed there. Unfortunately what I didn't know that when the river was at levels similar to the level we had during our October cruise, those boats didn't venture out of the harbor. I learned this fact later.
  I was creeping up the channel behind a large island that protects Piasa Harbor, heading in an upstream direction against the wind, my preferred approach in unfamiliar waters, as the depth finder kept recording lower and lower numbers, but before I could maneuver us out of another grounding, we lurched to a stop.
  All of my previous solutions to groundings entailed leaving the vessel and pushing in some manner. As I sat at the helm contemplating our circumstances, it was eerily quiet, even with the wind blowing. It was cold out, and I knew I had to get into the water, which in October is not an attractive course of action. Having no wet suit, and not wanting to sit around in cold wet clothing afterwards, I stripped off my clothes and descended the ladder into the water.
  As I had mentioned, the wind was blowing, but not really into the direction I wanted us to go, and there was very little current. In this slough, the mud was very deep, as there is generally little current to keep it washed out. I was mucking around in calf-deep goo searching for deeper water, but I knew the effort was senseless because the wind was going to take Swing Set where it wanted to before I could get back behind the helm anyway. The prospect of Rosie firing up the engines with me in the water was not to be considered.
  I pushed and shoved, and actually got Swing Set floating, but by the time I could climb into the boat, fire up the engines, and get us free, we were pushed into another shallow area by the wind.
   I still had the use of the marine radio as an option, and even though it was during the week; two rescue boats operate on the Alton Pool, and there was always the Coast Guard or Water Patrol as another option. But I am stubborn, and won't accept help until my last card is played, so I slipped back into the cold water and made another attempt at freeing Swing Set from our dilemma.
  I wound up doing this another time too, as I realized that even if a tow vessel was summoned, Swing Set was only leaving under her own power. Knowing that the bottom was mud about two feet thick, I fired up the Cats, put her in gear and drove us out of the mud, throwing all kinds of caution to the wind. Once I got into deeper water, I shut down the engines after deploying our anchor and visited the engine room.
  We were taking on water at the shaft seal on the starboard engine, but it wasn't enough that our bilge pumps couldn't keep up with. It wasn't until much later that I discovered why the shaft seal became twisted enough to leak, but I was able to get it back into place and stop the leaking. I pulled the sea strainers on both of the engines after closing the through hull valves and found them packed completely with river mud. 
  It took me several hours to get the strainers clean. I was able to use my fresh water supply on board to flush out the raw water intakes. I assembled everything and fired up one engine and checked for cooling water discharge. We have closed water cooling on Swing Set, which means that the sea water doesn't circulate through the engine block, but goes through a heat exchanger. Once I could see clean river water exiting the discharge ports, I felt confident enough to start up the other engine. I monitored the temperature gauges closely once we got under way.
  As the sun appeared late that afternoon, we were heading back upriver at idle speed, happy to be cruising again but were in no hurry. Because we were going so slow, it wasn't until the next spring when I found out the damage that our grounding had caused.

Appears to be the beard of Jone Paul Jones, but is actually a shredded barge line.

  Once we recommissioned Swing Set for the 2008 boating season, I noticed some vibration coming from the starboard running gear when we exceeded anything but idle speeds. The picture above shows what was left of a section of polypropylene barge line we dredged up when we plowed out of our nasty affair on the previous October.
  The vibration was caused strictly from the shredded remnant of line being tangled in the prop; the prop shafts were checked and were within specifications and the props were true. I still don't know how the dripless shaft seal started to leak, but it has behaved since; I have no qualms about it's integrity.
  The haul out was not in vain, however; we were due for a bottom paint anyway, so we contracted to have that work done to take advantage of the situation.
  In preparation for the extended cruising that we currently have planned, there are a couple of items that I have found necessary to purchase. Primarily, I obtained a wet suit. Never again do I want to enter water uncomfortably cold. We also got Rosie a wet suit too, but more from a snorkeling prospective rather than anything else.
  We also purchased a hookah type snorkeling outfit. It allows two divers to snorkel to depths of 30 feet with two 100 foot hoses and regulators. Our hookah operates on 110 volts, and our inverter will accommodate it for a while, and we can fire up the generator if we need to. The hookah will add to our list of fun stuff to do while at anchor in the more tropical areas of the world, and will also come in handy to free our running gear from unintentional passengers in the way of floating debris or lobster pots.
  I also intend to use the snorkel system to keep our hull free of barnacles that will grow there. It's a necessary chore; in some areas, it may need to be done monthly. Rafted up side by side with new found friends, we can spend whole afternoons scrubbing each others bottoms. Maybe we should get a sign made.

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