CD 28 & Shallow Slip???

[Ron Churgin]

Hi John,

Do you have tides in this river? If so, I imagine you measured at low tide. Take into account that tides are sometimes lower than the average around the full moon and in Spring and Fall.

I don't know how much loading gear into the boat will make it deeper in the water. If tides are only occaisionally lower, you can sometimes tie off the boat to some pilings to keep it from tipping.

[j2sailor]

Draft on small craft is measured from the waterline bootstripe to the lowest point of the hull, which on the Cape Dory is the flat run of the keel just forward of the rudder to the start of the cutaway.

When did you take your soundings? I would sound your slip at the next spring cycle (when the moon is new or full) during low water springs. Spring tides occur twice monthly, with lower low tides and higher high tides. This should give you a good idea of the lowest depths you could expect. Check your local paper or try this site: http://www.sunrisesunset.com/ It shows astronomical data, including moon phases and you can print a calendar for any month of the year.

If she'll berth in a slip, be sure to adjust the lines during low tide. Snug them up and she'll sit properly in her slip. Position fenders next to pilings and finger pier. Hang them horizontally adjacent to pilings (more fending surface area) and vertically next to the pier. Melbourne has soft mud so she'll be fine.

In Stuart, we had two fin keelers plus a Cape Dory at the school with barely enough water in their slips during normal high tide. Last summer, we experienced Perigean Springs (moon closest to earth in its revolution) during the full moon and the canal dried out severely. The slips ended up with about 3 feet of water and three well heeled sailing vessels, hard aground. Just use extra fenders at contact points and she should be fine..

Estimate your immersion by:
Multiplying waterline lenth x waterline beam x 75%. This gives Waterplane Area.
Multiply Waterplane Area x (64 / 12), or 5.3.

For instance, on the CD 28,
LWL = 22.2'.
Use 90% of beam to figure waterline beam: 8.9' x 90% = 8'.
22.2 x 8' = 177.6. 177.6 x 75% = 133.2 Waterplane Area
133.2 x 5.3 = 706 pounds to immerse her waterline by 1".

Hope that helps,
Cap'n J.

[Steve Laume]

I wish I had a cheap shallow slip close to my house. I can't imagine settling into soft mud would hurt your hull. I do wonder what a continuous diet of fine grit in the rudder shoe will do to the wear rate in the area. I would still go for the slip if I had a bunch of work to do on the boat. Any chance of diving in the slip and hand clearing the muck away from the rudder area once the boat is sitting in there? Maybe even a long handled clam rake could clear the rudder area. Don't tell Army Corp that I was suggesting you dredge your slip. If anyone asks just tell them you are clamming, Steve.

[Boyd]

Hi All:

The type of bottom makes a big difference. If its soft mud or sand you can use a L shaped PVC pipe to blow out a channel in the center of your slip. Its SOP a lot of places. Also you can have a power boat tied to the slip and run the engine a bit to make your channel.

My boat sat in a marina off Charleston Harbor for a long time. Never was aware that it sat on the bottom till I hauled her and found the mud line on the keel. The bottom was so soft that she would just plow her way into the slip.

If you have rock... forget it.

Boyd
s/v Tern
CD 30 MkII
Fort Lauderdale, Fla.

[Neil Gordon]

I would sound your slip at the next spring cycle (when the moon is new or full) during low water springs.

If you know the tidal range and have an almanac that covers the area you're interested in, you can measure anytime and calculate the rest from there.

[Dave Jeffery]

Where we are, up a shallow creek off Chesapeake Bay, wind can have a very large influence on tide rise and fall, hence depth.

The bottom is mud. Our boat, a CD 25, will sometimes ground out, but the longish keel just settles in without, so far, producing excessive tipping. (I can't imagine how a boat with a lead torpedo bulb at the end of a skinny keel would fare. Or an anchor-like wing keel, either.)

Dave J.

[Bryce Wentworth]

I had my CD28 in Merritt Island on the Indian River for quite some time. The river is not tidal so there is no concern for that issue. However, during droughts the depth can decrease considerably. What I found was that dragging the keel through the mud with the 13 hp Volvo and slightly fouled prop was a chore. You should also consider that the prop will kick up a lot silt at that depth, which will be sucked into the cooling system. You'll need to clean the exhaust manifold often.

[Dixon Hemphill]

I sail in the Chesapeake with my CD28 and occasionally go aground. No big deal! Because the bottom is mud I always manage to work the rudder back and forth and head out to deeper water with little trouble. More than once I have plowed thru water that read 3 1/2 feet on my depth mete without even slowing down. Of course if you have a rocky bottom NEVER attempt this manuever.

[Rebinva]

difference in the waterline.

[Bryce Wentworth]

Cleaning the manifold is not difficult just time consuming. Do a search on this board and you will find some posts on the process. As with anything, practise makes perfect.