V-Berth, Aft Locker, Holding Tank Shelf, Part I: Analysis

The large, aft locker beneath the V-berth: the logical location for the waste holding tank on an Ericson 25

It might not look like it, but the V-berth on an Ericson 25 is a spacious area of the boat, not only for sleeping, but also for the storage of various items. This is especially true in the lockers that are situated immediately beneath the V-shaped cushions - yes, those cushions on which you just might want to lay your weary head when the Admiral has claimed the settee berth (and its extension) in the main salon for herself.

While the V-berth itself is relatively large, the access to it is relatively small, since this access is framed by the hanging locker on the port side and the fully-enclosed head on the starboard. I'm a normal-sized, adult male, and I have never had any problems coming and going from the V-berth. I have had problems, however, working in this space, since it's often difficult to manipulate tools and the materials associated with epoxy without a lot of elbow room.

The V-berth cushions on the Ericson 25 rest upon a fiberglass deck of sorts. This deck is very strong, as it consists of balsa core-material sandwiched between layers of fiberglass. In this regard, this little V-berth deck, in its design and construction, is not unlike the deck on the exterior of the boat. The little deck in the V-berth has molded recesses that are intended to support pieces of plywood which serve as covers for the three lockers that are situated beneath the V-berth itself.

Below you see the three lockers. The fore-locker is quite small. The mid-locker is large enough for storing tool bags and other such items. The aft-locker is very generous in size. For this reason, it's not a bad place to locate the holding tank for the marine head, which, as I said, is in a fully-enclosed space on the starboard side of the boat beside this access point to the V-berth.

According to the official manual for the Ericson 25, it appears that any customer who paid extra to have a waste holding tank installed at the time of the commissioning of his boat would have had it installed by the dealer in this very locker in the way described below in the diagram.

Here's another view of this Ericson-authorized set-up for the holding tank. I won't get into the details of the plumbing in this article, but I would like to point out that the authorized set-up depicts a holding tank that is squatty in nature, in other words, a holding tank that is horizontally-oriented. Note that this horizontal orientation of the holding take results in much of the aft-locker being occupied by the tank. Keep this in mind when I later describe the vertically-oriented tank that I chose to install in this space in my Ericson 25.

As I said in an earlier article on the original plumbing of my boat at the time of purchase, my Ericson 25 did not possess an original factory-authorized holding tank. Instead, it had would would best be described as a fake holding tank installed by a previous owner. Apparently it was meant to pass a Coast Guard inspection in the event that the vessel was boarded by members of this organization. Despite the nasty looking hose that fed this fake tank, I found no evidence that the tank itself was ever used. It thus became clear to me that the previous owner simply pumped his waste directly overboard.

I myself planned to dump my waste directly overboard when legal and whenever able, but I also wanted to have a legitimate holding tank, especially for those times when docked at a marina, when flushing overboard would be not just illegal, but downright uncivilized. Therefore, it didn't take me long to decide to rip out that fake holding tank that had been so sloppily installed by the previous owner

There was also an outdated and semi-functional transducer down there that appeared to have been installed by the previous owner at some point. This too had to go.

Likewise there was a non-functional paddle-wheel knotmeter that did nothing but add junk to my boat. It also was destined for the trash can.

There was also a black plastic conduit in this large locker that had been used for routing the transducer and knotmeter cables aft to the instruments. This I needed to leave in place, since I would need to use it for the routing of any new cable or cables I would install.

I decided to invest in a GPS, not because I don't rely on traditional navigation or think that knowledge of it is unnecessary (like so many misguided souls these days), but because I considered it to be important for the safety of the boat and the crew in the event of several circumstances. One of these was fog, which would render the coastline and aids to navigation invisible. Another was rough weather in an anchorage, which could cause the boat to drag anchor. I figured I would sleep much better, if I knew that the GPS-activated anchor alarm would stir me from my slumber. Additionally, I should point out that I planed to wire this GPS to a VHF with DSC (Digital Selective Calling) capability. This would essentially provide me with EPIRB capability in coastal sailing situations. With the press of a button, the Coast Guard could be notified of my vessel's name, latitude, longitude, and other information. Yes, I believe it's foolish to be enslaved to a GPS for navigational purposes, but I do believe that a GPS is an important tool for safety's sake. After a lot of research, I opted for a Garmin GPSmap 541s.

In addition to the GPS, I also purchased a bronze Airmar B60-12, titled-element transducer. Airmar is an independent company that supplies Garmin with these products. I got a great deal, saving hundreds of dollars both on the transducer and on the GPS, by price-matching at West Marine. Ever since West Marine ended its price-matching policy, I have spent my money elsewhere. Too bad for them. They used to get about 90% of the money I spent on the refitting of my Ericson. Now they get zero, and I still save lots of money by ordering from other suppliers online.

Before I purchased the B60-12 transducer (that is designed for hulls with deadrises of 12 degrees or less), I thought it would be smart to determine, as exactly as possible, the deadrise of the Ericson 25. As you can tell from the picture below, the deadrise is 12 degrees. I don't know how anyone could ever figure this out with the boat not sitting on a trailer or on the hard.

When I picked up the B60-12 from West Marine, I was immediately impressed with its sturdiness.

Since my Ericson 25 never had a real holding tank, I needed to find one on my own - one that would be large enough for sufficient, temporary storage of waste, yet small enough to fit within the parameters of the aft-locker. I took many measurements of the aft-locker, and I compared these measurements to many a holding tank listed in the on-line catalogues. After much contemplation, I eventually settled on the Dometic SeaLand, 11 gallon, Vertical Holding Tank. Defender, the marine outfitter in Connecticut, is a supplier for Dometic, and when the price was right, I made the purchase. Dometic tanks are much thicker than your average tank, and I wanted a tank that would be both durable and less-likely to emit odors. I especially liked this particular Dometic tank, because of its vertical orientation. According to my measurements, it would fit well in the aft-locker of the V-berth on the Ericson 25, and I thought that it would do much to save space in this aft-locker that could be used for the storage of other items necessary for extended cruising.

After I received the Dometic holding tank in the mail, the first thing I needed to do was to figure how to mount the tank in the aft-locker. The picture below shows the deepest part of the aft-locker. I took the picture while sitting on the V-berth deck with my feet in the mid-locker. In other words, I was facing aft. This means that the piece of plywood in the picture is resting against the fiberglass bulkhead which separates the V-berth from the enclosed head (to the left in this picture) and the hanging locker (to the right). Please disregard the Trident brand sanitation hoses. I ordered those at a later date. This picture thus depicts the dry-fitting I had to perform in order to determine the best way to route the hoses. Let's ignore that for now and instead focus on the piece of plywood. I placed this plywood here temporarily, in order to protect the tank during the dry-fitting process. How, you might ask, would this protect the tank, and why would it need to be protected? Well, there are several screws that protrude into this space at this very point. These screws penetrate the fiberglass bulkhead, and their purpose is to secure the door frame for the enclosed head.

In the picture below we see the holding tank dry-fitted into place. Note that I have now replaced the rather large piece of plywood with a smaller piece. I figured that using a small piece would save a lot of weight. I realized, however, that I would need to make at least two other similarly-sized pieces of wood to go on either side of this center one. Otherwise, the holding tank would wobble and would be insecure. This was just the first of many pieces of wood I would need to cut in order to figure out how to hold this holding tank as securely as possible in place. The next thing I needed to figure out was how to construct a platform or shelf on which the holding tank could sit. It's difficult to see in this picture, but the only parts of the holding tank that are in contact with the hull of the boat are the outer edges on the bottom side. In other words, there is a sizable gap underneath the holding tank on account of the curvature of the hull. What I needed to do was to custom cut some wooden cleats and then glass them to the hull. To these cleats I could then secure a plywood platform that would serve as a level surface to which the tank could be secured with galvanized straps. That was my plan (at least in its initial stages), and now all I needed to do was to make it happen.

The picture below depicts the aft-locker as seen from the access point to the V-berth. In other words, here we are looking forward. Note how much space still remains in this large aft-locker. One thing that I wanted to figure out (while figuring out how to secure the holding tank) was how to make the most of this storage space. The through-hull would be filled by the new Airmar B60-12 transducer. I wanted to protect this transducer as much as possible, so I eventually decided that I would need to build a second platform or shelf that would cover it. This shelf, as I conceived it, would also serve to keep any item I might put into this space well elevated above the water that would be draining down from the chain locker into the bilge. All of this is difficult to picture without seeing the mock-ups and the pieces of wood in place. I'm only presenting this information right now, so that you can see how I was thinking through the problem.

In this picture we see the dry-fitted Trident brand sanitation hoses running toward the starboard side of the boat, where they make their turn and enter the enclosed head. It's not easy to ascertain from this picture, but there is a considerable amount of space between the side of the holding tank and the hull of the boat. To me, this could easily result in a lot of wasted space, if I did not make some sort of modification to make it more useful. Therefore, I decided that I should cut pieces of plywood that would hug or embrace the sides of the holding tank. These would help to keep the tank more secure. They would also serve as partitions that would create some amount of usable space behind them. Again, this is obviously difficult to imagine from my words alone. I'm simply including these descriptions at this point to show you how I thought through the problem. Let me tell you, I consumed more than one can of barley and hops at the end of more than one day to figure all this out, and even after I thought I had figured it all out, I needed to figure it out even more and make adjustments to the pieces that I had cut and fit and cut and refit. As I've said in other articles, forethought is everything, and the sipping of brew, in this boat-refitting context, often leads not to confusion but to greater clarity.

This ends the first part of this four-part article on how I modified the aft-locker in the V-berth of my Ericson 25, both to accommodate the vertically-mounted Dometic brand holding tank and to provide additional storage space for the many items necessary for extended cruising.