Can a Rigid Dinghy be made "Self Bailing" when left moored to the dock?

David_Old_Jersey · 17-02-2007, 04:12

Not exactly a sailing off into the WBY question............but I figure that as their are some clever folk here someone may have already come up with the solution.........or I will find that everyone else knows the answer

What would be useful is a rigid dinghy that I could leave moored to the dock in all weathers and when I returned to it was not half full of rain water or even semi submerged.

Over the years I have looked at other peoples dinghies and have yet to see a "solution". I am guessing that raising the floor above the waterline on a small dinghy (8 to 10 foot) so I could just leave a bung out to make it self draining would leave the vessel somewhat unstable, especially standing up.......

I am not after an automatic bilge pump. and would probably settle on "just" a few inches of water onboard, rather than half a dinghy.........

Any answer could be the tipping point for me to finaly turn some plywood into a dinghy. Possibly

seaclusion · 17-02-2007, 08:14

Raising the sole (floor) is the answer but it does present some problems. If you leave a drain plug out and the hole gets plugged with leaves your dinghy will fill with water and then the drain hole might be in free communication with the sea. Sinking therefore becomes a definate possibility. Unless the space between the bottom of the boat and the sole is enclosed completely or filled with closed cell foam and has enough reserve bouancy to float the weight of the dinghy so that it is above the drain hole she will surely rest on the bottom. (sorry about the longish answer).

As far as raising the level at which the passengers stand, this may not be a really bad problem depending upon the design of the hull. If the dinghy has a rather wide and flat bottom, raising the sole may only add two inches or so to the level at which you stand. OTOH if the hull is narrow and has a deep Vee the level will be raised considerably.

If you are starting out from scratch and designing and building the dinghy yourself, I'll bet you could come up with some hull that would work. Whether it would perform well in all conditions (be dry in a chop, stable when the wife steps on the gunnel) would be another story.

Richard

PS. I hate having to bail my dinghy after every rain and would love to see one that didn't need it.

seaclusion · 17-02-2007, 08:30

I built a 16' planing powerboat with a very shallow Vee bottom and the sole only an inch or so above the waterline. I made a small well, about 8" x 8" as I recall, on centerline and up against the transom. The drain hole was located in the transom at the bottom of the well. Water would accumulate in the well and when the boat was hauled on the trailer the drain plug was removed to release the water. Since the sole was above the waterline and the boat had positive floatation (to keep the sole above waterline) removing the plug while the boat was in the water did not sink her. An added benefit was that the plug could be removed while underway (on plane) and the accumulated water drained out.

Keep in mind this boat had a very shallow Vee and a very wide beam. Maybe something of this kind can be built into a small dinghy.

Richard

**S/V Elusive** · 17-02-2007, 09:42

I saw, the other day, a transom plug with a 'check' valve in it. When there is pressure greater on the inside, than the outside, water flows out. Otherwise, nothing flows in - there is also a screw on cap that can be put on for those of us who might not trust that while IN the dinghy.

Benny · 17-02-2007, 10:32

How about an all around cover that is propped up in the middle to allow rain pun off? Keeps water from entering instead of a way for it to exit. This work well on my dingy.

Boracay · 17-02-2007, 14:09

Those "air floor" inflatables look like the sole would be above the water line.
Something along those lines maybe.
The bottom compartment would need two drain plugs unless it was filled with foam.
Design would be easier if rowing was not a major option.
If it were beamy and the bottom compartment could be filled with water then it would be something like a liferaft.
Weight could get away from you unless construction was tightly controlled.

northerncat · 17-02-2007, 16:52

build one of these
sean

northerncat · 17-02-2007, 16:53

Mahna Mahna
doh

17-02-2007, 04:12	#1
David_Old_Jersey Registered User Join Date: Oct 2006 Location: Sailing to the Moon........ Boat: Yes - But tied to the Dock. Posts: 1,323 Images: 1	Can a Rigid Dinghy be made "Self Bailing" when left moored to the dock? Not exactly a sailing off into the WBY question............but I figure that as their are some clever folk here someone may have already come up with the solution.........or I will find that everyone else knows the answer What would be useful is a rigid dinghy that I could leave moored to the dock in all weathers and when I returned to it was not half full of rain water or even semi submerged. Over the years I have looked at other peoples dinghies and have yet to see a "solution". I am guessing that raising the floor above the waterline on a small dinghy (8 to 10 foot) so I could just leave a bung out to make it self draining would leave the vessel somewhat unstable, especially standing up....... I am not after an automatic bilge pump. and would probably settle on "just" a few inches of water onboard, rather than half a dinghy......... Any answer could be the tipping point for me to finaly turn some plywood into a dinghy. Possibly __________________ Open your mind, but not so far your brain falls out.

17-02-2007, 08:14	#2
seaclusion Registered User Join Date: Jul 2006 Location: Florida Boat: 36 gulfstar Posts: 67	Self-bailing dinghy Raising the sole (floor) is the answer but it does present some problems. If you leave a drain plug out and the hole gets plugged with leaves your dinghy will fill with water and then the drain hole might be in free communication with the sea. Sinking therefore becomes a definate possibility. Unless the space between the bottom of the boat and the sole is enclosed completely or filled with closed cell foam and has enough reserve bouancy to float the weight of the dinghy so that it is above the drain hole she will surely rest on the bottom. (sorry about the longish answer). As far as raising the level at which the passengers stand, this may not be a really bad problem depending upon the design of the hull. If the dinghy has a rather wide and flat bottom, raising the sole may only add two inches or so to the level at which you stand. OTOH if the hull is narrow and has a deep Vee the level will be raised considerably. If you are starting out from scratch and designing and building the dinghy yourself, I'll bet you could come up with some hull that would work. Whether it would perform well in all conditions (be dry in a chop, stable when the wife steps on the gunnel) would be another story. Richard PS. I hate having to bail my dinghy after every rain and would love to see one that didn't need it.

17-02-2007, 08:30	#3
seaclusion Registered User Join Date: Jul 2006 Location: Florida Boat: 36 gulfstar Posts: 67	A solution I built a 16' planing powerboat with a very shallow Vee bottom and the sole only an inch or so above the waterline. I made a small well, about 8" x 8" as I recall, on centerline and up against the transom. The drain hole was located in the transom at the bottom of the well. Water would accumulate in the well and when the boat was hauled on the trailer the drain plug was removed to release the water. Since the sole was above the waterline and the boat had positive floatation (to keep the sole above waterline) removing the plug while the boat was in the water did not sink her. An added benefit was that the plug could be removed while underway (on plane) and the accumulated water drained out. Keep in mind this boat had a very shallow Vee and a very wide beam. Maybe something of this kind can be built into a small dinghy. Richard

17-02-2007, 09:42	#4
S/V Elusive Moderator Site Helper Join Date: Apr 2006 Location: Ventura Harbor, CA Boat: Endeavour, Ketch, 43 ft., Elusive Posts: 2,247	I saw, the other day, a transom plug with a 'check' valve in it. When there is pressure greater on the inside, than the outside, water flows out. Otherwise, nothing flows in - there is also a screw on cap that can be put on for those of us who might not trust that while IN the dinghy. __________________ "The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails." - William Arthur Ward Thomas

17-02-2007, 10:32	#5
Benny Registered User Join Date: Jan 2007 Location: St Catharines ON, CAN Boat: Irwin 37 CC ketch 'Ta-Keel-Ah' Posts: 391	How about an all around cover that is propped up in the middle to allow rain pun off? Keeps water from entering instead of a way for it to exit. This work well on my dingy. __________________ Randy Benoit I37CC 'Ta-Keel-Ah' "I yam what I yam - and thas all what I yam" - Popeye

17-02-2007, 14:09	#6
Boracay Registered User Join Date: Feb 2004 Location: nr Blackwattle Bay,Sydney, NSW, Australia Boat: Steel Roberts Offshore 44 Posts: 1,248 Images: 12	"Air Floor"... Those "air floor" inflatables look like the sole would be above the water line. Something along those lines maybe. The bottom compartment would need two drain plugs unless it was filled with foam. Design would be easier if rowing was not a major option. If it were beamy and the bottom compartment could be filled with water then it would be something like a liferaft. Weight could get away from you unless construction was tightly controlled. __________________ Rust never sleeps Boracay Blog.

17-02-2007, 16:52	#7
northerncat Registered User Join Date: Aug 2006 Location: cairns australia Boat: now floating easy37 Posts: 636 Images: 41	build one of these sean

17-02-2007, 16:53	#8
northerncat Registered User Join Date: Aug 2006 Location: cairns australia Boat: now floating easy37 Posts: 636 Images: 41	Mahna Mahna doh

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