First, I came on board as a dealer just right after the discontinuance of the Hunter 22; therefore, I am not sure if the single or dual drain which came first. Further, the other thread mentioned has a response from Jcherubini whose father was the designer of Hunter sailboats long time back and his knowledge is valuable. Also credit is due to
@Hunter216 for the referral of an earlier post in the archives and
@isaksp00 for his information. Most particular gratification for
@Maxx Mayhem responding to my request for information.
This will be lengthy but should be informative. Earlier I referenced the Catalina 22 and Victoria 18 cockpit drains.
I am not sure if the single or dual drain system was first used on this Hunter 22. The single had a thru transom drain at the bottom of the transom wall just below the rudder fitting using a smaller opening. The dual had a single thru hull close up to the transom wall but in the hull itself. We are dealing with the two cockpit drain.
The early Catalina 22 cockpit drains were forward if memory serves me correctly with hoses either going to the hull or the back end of the transom wall. One problem if gone from the boat too long paticuraly during the fall when leaves are falling, those darn drains would become clogged and water would fill up to the point overflowing into the cabin. Later, Catalina went to the two drains thru the transom from the cockpit spilling out directly into the water with no screens to avoid earlier issues of the screens being clogged by leaves and in one case I knew of duck nesting over the drains laying eggs and water spilled into the cabin (That really stunk but did emergency repairs at no charge to the owner without permission to keep boat from sinking). Due to in a sense the cockpit floor was higher from the water, the transom drains worked fine on the newer style Catalina 22 regardless of heavy seas or extra weight in the cockpit.
The Victoria 18 is a smaller boat with two drains with screens in the forward cockpit floor with the cockpit floor being lower to the water line. Therefore, transom drains would not work as heavy seas and a lot of weight in the cockpit, water would flow into the cockpit from transom straight thru drains. Therefore, the drain hoses criss crossed each other thru seacock style thru hulls. The reason why this was done that way was to mitigate the amount of water back flowing into the cockpit. For example the starboard cockpit drain is raised up draining thru the port side where it drains out which is on the lower side in the wate; thus, the back wash is pretty much nill. However, if gone too long again during the fall season with leaves falling, drains could become clogged up by leaves and thus the possiblilty of water flowing into the cabin once the cockpit is full of water.
In this case, we are dealing with a dual drain in the cockpit floor with those darn screens again that connects to a T fitting leading to a thru hull fitting forward of the transom wall. The T is lower than the thru hull drain and as pointed out difficult to get to unless you are a munchkin or water left standing that could freeze up during winter depending where you are at, thus the cockpit floor drains would be rendered useless in the event of inclement weather unless the boat is stored inside or covered up to the point no rain, snow and so on can get to the cockpit floor.
First I would install an opening port or deck plate as shown in the referenced thread on the inside of the cockpit transom wall to allow easier access to the rudder fittings and the attachment of the hoses. I would go with a 5 or most preferably a 6 inch plate. That was a good suggestion.
The single cockpit floor drain is centered with a new hose to a T fitting that is higher than the transom wall drain. I would have done that differently eliminating the T fitting. First I would have removed that thru cockpit floor fitting as the threaded portion of that fitting underneath the cockpit floor extended too far down. There are others with shorter threads that I would use. Therefore, the possibility of the T could be eliminated with a single hose in a moderate bend without collapsing the wall of the hose could go direct to the thru transom drain to avoid any constriction. The use of double clamping in opposite directions beside each other is industry standard as if one came loose, the other would be holding.
Back to the dual thru cockpit drain connected by hoses leading to a T which is below the thru hull drain. I bet that was done to help prevent backwash from following heavy seas and any added weight in access of what is normal for that size cockpit as the T was much lower. However the issue of freezing is a major concern to me. In addition, I am not sure if thru transom drains for example like the Catalina 22 mentioned earlier (newer style) would be appropriate. Why? It appears from the picture Maxx Mayhem supplied of the transom wall, the cockpit drains are lower to the waterline; thus the issues of water coming in from heavy following seas and any added weight. I reflect back on the daysailors with cockpit thru transom drains being so close to the water line filling up the cockpit with weight in the back. I suggested open transoms but with the cockpit floor higher in the daysailors that Hunter built to help avoid that. In addition, a larger thru hull in the center of the transom below the rudder fitting might weaken that portion of the transom wall. One thing to note though, the hull when laid, I recall if correct the transom was all part of the hull when it was glassed or in other words, mfg. as one section.
The easiest way to repair is what the previous owner did replacing the lines, T and adding two clamps as noted earlier in this post in opposite directions side by side of course. I would add the inspection port. That is one way but the boat should be removed in winter if freezing could occur to the point that the T would not freeze up. In moderate weather where it does get cold but little freezing, generally the water temperaturer is warmer than the outside temperature; thus the worry of the T freezing may never happen as the discharge is thru hull under the water line.
There is another way reflecting back on what was said by others and what I remember of the Victoria 18 hosing crisscrossing each other to the opposite sides of the hulls. First, Attwood, Forespar, T-H Marine, Seafit, Marine East and others offer a 90 degree barb mushroom head thru hull fittings with barbs. Secondly, I would add the transom opening port deck plate as previously mentioned. Personally if keeping the boat, I would look for easy access to the hull forward of the transom but much further forward of the current thru hull drain with easy access from within the cabin. I would then install the appropriate size thru hull 90 degree mushroom head with barb fittings with each one pointing to the opposite side drain. For example the thru hull new drain on the port side would be pointed to the starboard drain. I would then add the appropriate size hose being a single run from the starboard cockpit drain to the thru hull fitting on the port side and of course double clamped. You will have to secure the hoses. Also, I would glass in the old hull drain, apply barrier coats and of course anti fouling.
I will encourage Maxx Mayhem to send me a private message with phone number if he has any further questions.
Dave