The cockpit drain pipe on my boat is shaped a lot like a p-trap on a sink. I am wondering if straightening the run of the pipe might improve my situation. Remembering back to sailing on my Minifish when I was younger opening up the drainplug when moving at decent clip the water would suck right out of the cockpit if there was any in there at the time. I was not getting that kind of effect yesterday though I was definitely moving at a decent clip. On Thu, Aug 2, 2018, 4:17 PM Lawrence Winiarski via montgomery_boats, < montgomery_boats@mailman.xmission.com> wrote:
I have an M15 and never have the flooding issue unless I'm moving at a good clip and sitting toward the stern and/or havea very large passenger. I worked out a pitot tube equation and it's about 3-4 inches static pressure at 3mph, so I thinkthat could be a contributing factor for the flooding.
I wonder some holes would be enough of a venturi effect to reverse this.. Be cool if it worked.
Thanks again Dave.
From: Dave Scobie <scoobscobie@gmail.com> To: Lawrence Winiarski <lawrence_winiarski@yahoo.com>; For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Sent: Thursday, August 2, 2018 2:52 PM Subject: Re: M_Boats: Cockpit Drain
The issue is the cockpit floor is low.witj just a bit of slope when the boat is sitting her lines (no people at a dock). Jerry did this to limit freeboard (more windage, more heeling, poor windward ability, etc.) And have a deep foot well (comfort). A series of trade-offs. The keel is filled with steel punchings or lead BBs (depending on age). Using 'Venturi' systems requires speed and if the boat not going fast enough you end up with more holes below the waterline ...
:: Dave Scobie :: M17 #375 SWEET PEA - m17-375.com
On Thu, Aug 2, 2018, 2:18 PM Lawrence Winiarski via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
What is the construction of the semi-keel part of the boat (the permanent partial keel that the drop-down keel fits up into? Is it solid or hollow or cored? Could a person put a hole in the side, near the hull into the keel storage area fairly easily?
The reason I'm asking is because I had an idea, that the water back flowing into the cockpit happens because the static pressureat the drain rises and the boat itself squats down a little bit.
But, suppose you made 2 holes through the partial keel, into the port and starboard up as high as possible near the keel raising rope/drain where the water pressure is going to form a natural low as it rushes along the sides of the keel?
Could this lower the static pressure at the drain enough to mitigate the flooding?
From: Dave Scobie <scoobscobie@gmail.com> To: For and about Montgomery Sailboats < montgomery_boats@mailman.xmission.com> Sent: Thursday, August 2, 2018 1:34 PM Subject: Re: M_Boats: Cockpit Drain
Simple answer is the cockpit floors have greater slope towards the drains and are higher above the waterlines.
:: Dave Scobie :: M17 #375 SWEET PEA - m17-375.com
On Thu, Aug 2, 2018, 1:27 PM Jason Leckie <leckie.jas@gmail.com> wrote:
Dave:
Hmm, ok, good to know. How does the newer Sage cockpit drain get around this?
I see now that the plugs that came with the boat are there for good reason..
On Thu, Aug 2, 2018, 1:03 PM Jason Leckie, <leckie.jas@gmail.com> wrote:
Hi All, its me again,
I certainly seem to have no shortage of questions for this forum. I was out for a sail off of Point Roberts yesterday in a pretty good breeze, maybe 15 knots and found my M17 to sail quite nicely indeed. This was essentially my first sail on my new boat and she performed admirably.
At the same time though, a new issue popped up. The cockpit drain is acting like the opposite of a drain and the cockpit was taking on water. Back at port, when sitting in the cockpit, the water in the drain pipe, is sits just below the level of the cockpit floor.
I presume a previous owner of this boat did some work on this part of the boat and is no longer configured as originally manufactured.
What is the correct configuration of this pipe? The thru hull fitting is located way below the water line, which I am guessing is not a problem as long as it is configured correctly. Do these drains ever have check valves installed on them?
Thanks in advance for everyone's input.
Jason Leckie 1980 M17 'Kuma' Point Roberts, WA