Kent Narrows - Local Knowledge Needed

[T37Chef]

Clay/aa3jy,

I made a mistake, I assumed that when anyone was referring to depth of water they were referring to the the depth of the water and not a reading on their instrument?

Not to take the thread to much off topic...but I would ask what is good practice/seamanship then? Calibrating an instrument from waterline? keel? thu hull? etc?

What say you?

[chef2sail]

Let me see here....I havent seen to many coral heads recently except when i have chartered in the Carribean. However when we go on our trip to NEngland ever summer, we often enter unknown areas where there is no soft grounding...just rocks.

For this reason as previously stated I set my depth finder to read from the waterline of the boat. ( Thats where the surface is...the same place the measure from when making the charts using MLW)

I lokked in the mirror this morning and didnt see an orangutan....but I did notice a bit of an orange in my shaving cream......**:**).

Dave

[aa3jy]

To add to the confusion..

Measuring Draft [Archive] - SailboatOwners.com

Load Water Line (amount of hair curling irons and such on board)is also affected by the amount salinity (density)as well as temp differences..calibrating for water line in the upper part of the Bay will be different as one travels south and visa versa.

That's why you will see Plimsoll Lines on ships..

Waterline - Wikipedia, the free encyclopedia

I for one want to know the amount clearance between my keel and bottom..accurately calibrating for water line is a constant process.

Regards,

Clay
s/v 'Tango'

[T37Chef]

UH???? Time for a new thread...go for it Clay

[sck5]

I used to set the depth sounder to the surface of the water so it would be at the same reference as the charts. Last year I got a new depth instrument and decided to leave it at the zero offset the factory sent it with. That way I have an extra 18 inches or so of water beyond what the instrument says. Its good insurance. I know that it is set that way - visitors dont so they are a little more careful which is how I want them to be.

[T37Chef]

BTW...back on topic, as mentioned above, beware the red 6 is missing its light and marker
See here:

[aa3jy]

Originally Posted by captainrizzo

Greetings all. I am looking for some local knowledge for navigating Kent Narrows. My current plan for Memorial Day weekend is to sail NE from Annapolis, around Love Point, and then due S to the Narrows, under the Route 50/301 bridge and pass through the drawbridge. I know that the current can be quite strong and should attempt to pass during slack tide. If I can't hit slack tide, should I err on the side of ebb or flood tide? How much reliance can I place on the tide forecasts? Any other help or suggestions would be greatly appreciated. My boat draws just shy of 4 feet, LOA is 30 feet with a beam of 11 feet, and bridge clearance is 44 feet. I have charts as well as the Chesapeake cruising guide for 2010. Many thanks in advance.

Call the bridge tender on Channel 13 they appreciate it and they log the traffic that passes.

Expect to circle with the rest of the crowd that either have masts or refuse to lower their (movable) antennas..the bridge opens on the hour and half hour and only stay open for about 10 mins. If your approaching from the most outer day marks don't expect to have the bridge to remain open.

Those on the side of the bridge that have the current (generally) have the 'right-of-way' of going first. Though there are some that refuse and can't wait..

If your the last in line make sure you clear the bridge there has been some instances of the bridge descending on masts.

Yes..I have "Local Knowledge".. I've sat on the front porch of Piney Narrows Yacht Haven(across from Red Eyes Bar and Grill)on major weekends and watch the antics and listen on a portable radio..

Oh..and expect the MRP to watching that weekend 'cause they have a boat ramp right next to Piney Narrows YH..

Regards,

Clay
s/v 'Tango'

[PalmettoSailor]

Originally Posted by aa3jy

To add to the confusion..

Measuring Draft [Archive] - SailboatOwners.com

Load Water Line (amount of hair curling irons and such on board)is also affected by the amount salinity (density)as well as temp differences..calibrating for water line in the upper part of the Bay will be different as one travels south and visa versa.

That's why you will see Plimsoll Lines on ships..

Waterline - Wikipedia, the free encyclopedia

I for one want to know the amount clearance between my keel and bottom..accurately calibrating for water line is a constant process.

Regards,

Clay
s/v 'Tango'

I get what your argument is, but don't really buy it for a midsized sailboat. The factors you mention will affect the depth of my keel by only a matter of inches. Variables such as wind and tide will have a greater affect on the water depth. I find it much easier to have the sounder set for the approximate water line which makes tasks like running a contour line while watching a chart a simple exercise

If you sail in an area of rocks or coral, you need to be leaving a fudge factor of more than a few inches anyway, since you don't know the exact state of the tide or how accurate the sounding really is. Also a rock or coral head can rise up in a way that the depth sounder would tell you about it about the time the keel contacted it, so fudge factors measured in feet are prudent. Worrying about load or salinity impacts on a 30-40 foot boat is like measuring with a micrometer to cut with a chainsaw.

If you like measuring depth from the base of the keel, then adding to approximate the surface for chart work, good on ya', but I find it just as easy to subtract my draw plus a fudge factor to approximate the bottom. There is some SWAG work involved either way you go.

[T37Chef]

Originally Posted by aa3jy

Oh..and expect the MRP to watching that weekend 'cause they have a boat ramp right next to Piney Narrows YH..

Don't you mean the DNR Police?

[aa3jy]

Originally Posted by T37Chef

Don't you mean the DNR Police?

Nope..I meant NRP..the "Enforcement Arm of the DNR"..

Maryland Department of Natural Resources - Natural Resoueces Police