Chines and tracking

[westward]

Greetings. Here's another possible solution to handling problems in larger seas: Run with a prop that's as low pitch as your general boating will allow. I don't know - you may already be doing this. The effect is to "downshift" your engine and therefore give you quicker throttle response, the ability to stay on/climb the backside of waves in a following sea, better load handling, etc. We almost always run heavily loaded and often in rough seas, so I tend to choose the lowest pitch prop of the range normally recommended. Good luck! Mike.

[Capt. Jim]

bmacpiper;
Keep in mind that you are in a very small boat. Those responding to your inquiry are runnirg 22 and 25 foot boats. There is a world of difference in what you can do in a 22-25 foot boat compared to a 16.
Am advice is to accept tour boat's limitations or move up. As for myself, I have traveled the other direction, 22 Whaler to 17 Arima to 16 C -Dory and an having the most fun ever!

[tsturm]

[thataway]

bmacpiper
Capt Jim noted something which I was going to also note. The boats do not "scale" up and down exactly--ie the way the 16 handles does not necessarilly relate to the way the 22 and 25 handle. (and they are not exactly the same either).

The 16 is a small boat--especially for heavy seas. I had a 16 foot dory, which I used to row at least 6 miles a day--sometimes in the open ocean where it was rough. The Grand Banks fishermen trusted their lives to the dory configuration, as did the early attempts to row across the Atlantic Ocean. The reason is that the dory hull slips sideways when on a wave, it does not dig in, it does not trip. The semi dory has a wider stern, than the "tomb stone" transom of a dory. I suggest you by a book, by David Gerr; "The nature of boats". David Gerr is a very good Naval Archetect who explains hull types. A true multi chine boat, has semi rounded "sides" where the hull attatches to the bottom. The C Dory has almost a flat bottom (some rocker fore and aft)--with an abrupt angle at the sides. A multi chine boat, would have several pannels where there is a transition to the side of the boat, and is usually a semi displacement boat.

The strakes will modify the way that water flow under the craft, and it may make the boat "squirley" at higher speeds, They may "dig" in just when you want the boat to slide sideways.

The alternative to sliding, is for the boat to heel, or for the boat to dig in. This can cause the boat to broach or to capsize. The "cork" effect of the flat bottom, is what makes the C Dory so sea worthy. The ability to slide down the face of a wave, without broaching or digging also adds to this seaworthyness. The origional 22's were more of a true semi dory, with no "v" foreward--this caused slightly more pounding, but had some other virtues...so there are always trade offs.

When we were building boats, we had shared space with a number of other builders--and some folks came in and modified their boats. Many times the boats behaved poorly afterwards--same for amateur designed boats--"new and novel ideas"--the could not sell the boat afterward.

In order to modify your boat, you would have to grind down the boat to the glass. Then glue in place foam or wood for the "forum", and then cover this forum, with glass and epoxy. This would have to be faired in with the rest of the bottom of the boat. You should not screw anything to the bottom of a C Dory for the risk of water intrustion into the Balsa core. Probably the best way to do what you want to do, is to turn the boat upside down. Then you can use weights to hold the material in place while the epoxy goes off on the forum which forms the "new" strake.

Trimming up--just enough to bring the bow up, not to bring the prop out of the water. In fact you want to avoid bringing the props out of the water.

Heavy seas--we were caught in hurricane force winds crossing the Atlantic East bound. (not in a C Dory) We kept the boat on autopilot except when the dog had to go to the bathroom...Then I had steered, and took the boat straight down the seas (40 to 45 feet and breaking) and I attempted to keep any waves from breaking on the boat. The boat rolled to 90 degrees once--and over 75 degrees a number of times. A well designed boat, handled properly will handle a lot of heavy seas, and survive.

[Doryman]

[bmacpiper]

thataway,
Thanks, that helps a lot to let me visualize what's going on.

Mind you, I run mainly in protected waters, but they get plenty bad for a little 16 footer. As many have noted, I am sure the 16 moves around more quickly/suddenly in rough seas (narrower beam, lighter weight), so here's one more question for you and the collective.

What about the possibility of using a drogue if caught in really bad stuff? For the record, my definition of a drogue is basically a sea anchor with a bigger hole in it, to allow use when a boat is making way with it deployed.

The thought here, based on your comments, would be to slow down the real sudden roll and yaw (in particular the yaw), but not add anything to the hull that would cause it to trip down the face of a wave, etc.

I've also seen a rig a time or two (intended for boats without power) that involved a triangle from bow to stern, with a pulley in the middle of the triangle. On the other side of the pulley was about 100' of line to a sea anchor. By adjusting the pulley's position, the operator could keep the boat a given angle off the seas when the motor had died, i.e. not with the seas directly behind as would be the case with a traditional sea anchor setup. It also seemed to create a slick to the windward side, which helped as well to keep seas from breaking next to the boat.

Here again, how about replacing the sea anchor with a drogue to allow use of the motor (slowly), but still get some assistance holding the stern in place as waves slide by?

OK, I promise this is my last post about this--but it is an interesting one for me.

Thanks and talk soon,
bmc

[DaveS]

bmc,
As a former owner of a 16' Cruiser, I too was concerned about being caught out in "perilous seas". (Even had a drogue that I carried on board.......never used it and it just took up more space on a small vessel).

Since we cruise in the same waters, I found that there were times that it was just plan smart to not venture out, the few times that I did get "caught" out in conditions that created a bit of "pucker factor", I was always able to cruise to a protected area and sit tight until conditions improved. (That is one of the many joys of cruising in the Puget Sound and San Juans.....you are never far from a "safe harbor").

It is may opinion the 16' C-Dory will take a lot more turbulence than most all other 16' brands.....but remember it is "just 16' ".

Bottom line to me is to enjoy the 16' as it is, don't get too carried away with filling the small storage space you have by toting around too much of the "extra what if equipment".

One of the reasons we "traded up" to the 22' was so we could feel a bit safer out there and take a little more weather. (Now I just have to keep reminding myself that it is "just 22'" ) .

[bmacpiper]

Thanks, Dave. You remind me of the plaque mentioned in a previous post: "Oh lord, thy sea is so big, and my boat so very small..."

tx,
bmc

[thataway]

If you want to read about drogues and proper use, get Earl Hinz's book Heavy Weather Tactics using Sea Anchors and Drogues. But I would not use a drogue on a C Dory. If you want to use a sea anchor--ok--but a drogue will put you at some risk. The most vulnerable part of the boat is the transom--and with a relitatively low transom, you have the risk of a breaking sea comming over the splash well, and getting into a non self bailing boat. Most boats which use drogues, these days, use the Jordan series drogues--these are multiple small drogues, which are space out over a long line.
See; http://www.jordanseriesdrogue.com/

If you are in "ultimate condtions" this is one place where I would consider a real sea anchor. But these have their problems also--one is chafe, another is how to deploy, and how to retrieve, and finally exactly how to position the boat for best safety.

[DaveS]

[DaveS]

[ffheap]

Hi Folks,

While we are talking about heavy weather cruising, If you can find an earlier edition of Chapman's Piloting Seamanship and Small Boat Handling (1965 or earlier), there is a great article about running inlets. It is in reality an article about heavy weather sailing with a power boat. This is what I used on my trip across Nantucket Sound including running half way up a wave as I was going into Nantucket Channel.

The later copies still have info under the Seamanship chapter. From what I have seen, the newer the copy, the less about heavy weather sailing.

Fred

[dotnmarty]

I don't know if this relates directly, but the most significant handling change I made to our 16 was the addition of the Permatrim. "Don't leave home without it".