|Our Hobie Tandem Island, gunkholing around Wreck Island, Virginia in 2010|
Gybe the sailor posted the following questions to my shoal draft blog entry of yesterday:
is your goal to sail in skinny water (under a fathom) or maneuver to your slip?
Seriously, are you ready to sail a Southerly 115 at six knots across 4′ water? Don’t forget ground effect.
Before I address anything else, which aspect of ground effect — negative lift or positive lift — are you referring to? I’m familiar with both in reference to auto racing and aircraft, but not specifically in reference to boats in shallow water. Can you elaborate?
While we did manage 9+ knots in about 30 inches of water with our Hobie Tandem Island down at Magothy Bay, Virginia a couple of years ago (you can read here about our adventures during that trip), our ultimate goal is not high speed sailing in 4′ of water with a 34+ foot displacement hull sailboat.
One of the huge selling points of the Tandem Island sailing kayak for us was it’s virtual lack of draft — just 6 inches with the centerboard and rudder up, and 26 inches with both of them fully down. That extreme shoal draft was instrumental with re-igniting Cindy’s interest in sailing and getting out on the water — and more importantly — to explore the places that are hard to reach, to see the multitude of Bay critters in their natural surroundings, and to get away from the crowds with the deeper draft rigs. New readers can watch all of our thin water explorations via the entries on Our YouTube videos page.
Below is another way of looking at the issue; I’ve posted screen grabs of Maryland’s lower Eastern Shore from the Navionics navigation app I use on my iPhone. The top image is has the safety depth (in blue) set at 6 feet, which is just 20 inches deeper than the 4’4″ draft of our Pearson 303. The bottom image has the safety depth completely removed and represents what we can explore with the Tandem Island.
|The blue areas represent depths of 6 feet or less|
|The shoaling danger areas virtually vanish with our Tandem Island|
The image below of roughly the same region within the Chesapeake as above was created using Google Earth, which I overlayed with bathymetric data provided by the state of Maryland via NOAA. The darkest orange color indicates depths of 5.2 feet or less, and the dark blue sections represent the major deep water channels within the Bay. As you can see, there’s a lot of thin water on the Eastern Shore.
|Google Earth with NOAA bathymetric data
And before you can point it out to me — yes, we may already explore the Chesapeake Bay skinny water areas with our present selection of thin water boats:
- Hobie Mirage Tandem Island sailing kayak — 6 inches draft with the boards up, and 26 inches with both of them fully down. This 18 foot long mini-trimaran is big enough for both of us and we’ve been able to sail her 32 miles in 4.5 hours, so we know something of her capabilities.
- Hobie Mirage Revolution 13 kayak — This is Cindy’s baby and when she’s using it, she draws about 3 inches with the boards up and 20 inches with the Mirage drive down. Her longest distance is covered with the Revo 13 so far is about 8 miles.
- Portland Pudgy dinghy — This one is a new-to-us used model that we have yet to take out and get familiar with, but she draws about 6 inches with the boards up and about 20 inches with them down. She can be rowed, sailed, sculled, paddled and/or powered (with an optional outboard motor), so we don’t really know what her distance limits are.
- Sara — Our ancient 8 foot fiberglass rowing dinghy that was included with our Pearson 303 purchase; she draws about 8 inches with me in it and is so unstable that we don’t dare add a second passenger. My best distance so far with her is about 3 miles.
However, we discovered very quickly over the past three years that the little boats seriously lack amenities when bio breaks are required, or when some shade would be nice to escape the midday sun, or when you just want to stay out from shore and never have the nature experience end. That is why we want a shoal draft mothership… to get a lot closer to the thin water action with all — or at least some — of the comforts of home.
Twitch Cove, on eastern side of Smith Island, Maryland (see the Google map below) is one of the areas we’d like to explore in a shallow draft mothership, but we know from sailing there in the Tandem Island in July of 2010 that the shoals surrounding that area are a real challenge for anything with a draft over 4 feet (you can read here about us touching bottom with the centerboard of the TI when the charts indicated we were supposed to be in 5 or 6 feet of water). We also know that getting there from Crisfield in a tiny thin water boat represents some serious effort and desire, as the roundtrip distance — without any additional exploring — is right at 14 miles.
Cindy and I have discussed in exhaustive detail for many months what we want in a bigger boat, but the number one critical selection criteria for us has been — and will continue to be — shoal draft. Not blue water sea handling qualities. Not how many guests can stay aboard. Not the plotted speeds on a polar chart. Not build quality. No, for us the number one criteria keeps boiling back down to shoal draft and how we can most affordably obtain it in something that’s bigger than the Pearson 303 we currently own.
And toward that end, we continue to look at everything out there that offers us the best solution to our quest for a shoal draft mothership. Cindy has even revisited the idea of us possibly buying a used Gemini 105Mc catamaran, simply because they draw 18 inches with the boards up and offer just about the perfect platform available for thin water gunkholing on the Chesapeake.