Gizmo's air draft sensor & my Panbo 8th

... written for Panbo by Ben Ellison and posted on Apr 14, 2013
Lafayette_River_trawler_bridge_cPanbo_.jpg

This was Thursday's little challenge. It's what I've starting calling a "trawler bridge": a span high enough to let motor cruisers get at some good anchoring and/or gunkholing, but not so high that they have to share it with pesky sailboats. I kid, of course, but I had spied out a great little spot on Norfolk's Lafayette River (Google Map here) to ride out the frontal passage and it would likely be free because there's only 24-feet under this bridge at high tide. However, I wasn't absolutely sure that Gizmo's mighty antenna farm met that requirement...

I've somehow never gotten an accurate measure of Gizmo's air draft, and apparently I'd developed an exaggerated idea of what it was. That and some "typical man" jibes (fair enough) were the content of a pretty funny conversation I had with a North Carolina bridge keeper who didn't want to open for me.  After I nervously made it under -- even though a guy working on the bridge waved me back at one point -- the keeper estimated Gizmo's height at 24-feet. If that was true I had about 2-feet of low tide extra en route to the sweet anchorage...

Gizmo_custom_air_draft_sensor_cPanbo.jpg

But if it wasn't true, bad things could happen. So I anchored briefly outside the bridge, climbed up the mast and taped a stick higher than the lightning protector and leaning forward. I also folded back the bimini so I could monitor my sensor as I slowly approached the bridge. Heck, the stick didn't even touch, so my mast may be even shorter than I thought (unfortunately, this bridge does not have a handy tide gauge so the calibration is not complete).

Gizmo's_dink_with_Torqeedo_1003_cPanbo.jpg

Size issues aside, I became a happy guy snugly anchored alone through the blow. It was also a good workout for the little Bolger-designed Nymph tender and confirmation that that universal-jointed tiller extension (stumbled upon in the Oriental Marine Consignment shop) is indeed the solution to the Torqeedo steering issue I fretted about last fallNow I can run the Torqeedo from several positions, even standing up, and I might add that it took only about 12% battery life and 12 minutes to make it almost a mile to the dinghy float at O'Sullivan's Wharf restaurant, and the engine started every time. The motor can still develop a noisy battery overload condition at high rpms but that hasn't changed almost since I started long testing it in in early 2011 and I still like it so much that I'm reluctant to send it in for servicing.

Alchemy_in_Belhaven_NC_cPanbo.jpg

At any rate, despite wind and rain Friday turned out to be great lay day for reminiscing on my eighth year at Panbo. It's been neat meeting readers during the trip, like Chris and Gretchen Witzgall who unfortunately arrived in Belhaven aboard their sharply tricked-out Alchemy (above) just as I was leaving. I did learn, though, that Chris scored that Simrad Broadband Radar in the Panbo Classifieds (they're free, folks, and though not used much, they often work). Hopefully, Gizmo and Alchemy will meet again further up the road and maybe we can learn more about all that gadgetry.
  I also got to know the low-key college neighborhood along the Lafayette River a bit and learned about Norfolk history and the wild world of satellite communications over lunch with Jim Rhodes, a true Southern gentleman and scholar of public relations. Jim has many years experience aboard Navy vessels large and small but I'm not sure even he'd know what all the gizmos are on this small but fearsome-looking war boat I passed on the ICW. Anyone?

U.S._Navy_war_craft_in_Norfolk_cPanbo.jpg

Comments

I've had lot's of doubts (in a pesky sailboat…) trying feel good about going under a bridge. It would be really nice to know exactly how much clearance I have.

BTW, the last photo looks like the marines spending taxpayer money to practice defending the USA against a few turban-headed goat herders.

;=}

Posted by: Fred at April 14, 2013 1:24 PM | Reply

Hi Ben.

I don't see too many gizmos on that RIB. Other than the antennas, whose frequencies a I would expect a HAM guy to be able to estimate by their length, I spotted only a radome and what appears to be a FLIR unit. There must be a GPS somewhere, but I don't see it unless it's atop the radome.

Bow guns are an M240 machine gun and an M134 minigun, both 7.62mm. The aft gun is a .50 caliber M2.

/afb

Posted by: Adam at April 14, 2013 2:29 PM | Reply

A radome? Maybe, but not like any I've seen before, and there may be something else in that odd casing. I'm also not certain that those are normal spotlights on either side of what is probably a thermal camera.

Posted by: Ben E in reply to Adam at April 14, 2013 3:18 PM | Reply

You certainly could be right, Ben. I just assumed we were looking at typical heavy duty military enclosures.

As for the spotlights, they look to me like they've been turned around to face aft, but I'm sure in any case they'll have infrared filters.

Posted by: Adam at April 14, 2013 3:32 PM | Reply

Not the Marines, that's the good old United States Navy...

http://www.rivronone.navy.mil/

Posted by: Carl at April 14, 2013 4:35 PM | Reply

You got it, Carl; I also saw the other boat shown with the unit. Wikipedia some detail on this boat, which is known as a SURC (small unit riverine craft)

http://en.wikipedia.org/wiki/Small_unit_riverine_craft

Most pictures show SURC's with conventional Raymarine radars.

Posted by: Ben E in reply to Carl at April 14, 2013 5:15 PM | Reply

Ben,

I purchased a Lieca Disto plus laser ditancemeter to take the lines of a boat a few years ago. Handiest tool to have. It is accurate to 1.5mm (1/16") at 200 m (656') You can shoot multiples and it does Pythagoras, volume, tracking, etc, etc. It outputs bluetooth to a CSV or Excel type. I paid hundreds more than they can be had today. 1st job paid for it the first day. Invaluable when building off things that aren't plumb, true, etc. Instantly put my mast height (lite) at 41.25'

Best Regards
Bill

--
Bill Taylor
VP Engineering
TTA MARINE LLC
Holiday, Fl

Posted by: Bill Taylor at April 15, 2013 2:01 PM | Reply

Ben,
That's a nice looking Nymph. That boat rows really well, but I've never thought of putting an outboard on mine. However, I see that it least it floats level with the Torqueedo on the back!
Bruce

Posted by: Bruce Hays at April 15, 2013 3:03 PM | Reply

Nice photo of your OCC Burgee. Now I know I was interpreting your occasional jibes at sailboats correctly, even without the :-)'s.

Mark.

Posted by: Mark Morwood at April 16, 2013 10:40 PM | Reply

The Navy SURC is clearly running the very latest dual DragonFly displays. No more Furuno thanks to the automatic budget cuts!

Posted by: Patrick at April 17, 2013 12:46 PM | Reply

Thanks to Sherri & Nick for sending more air draft measuring solutions (by email):

"1 Put boat in a covered slip (pilings generally go taller than boat)
2 Get a laser level - the kind that self levels (most of them do) - at home depot
3 Hang level from boat hook on a line
4 Lift to top point on mast
5 Mark spot on piling - best done when dark
6 Measure spot on piling

Another technique many new Krogen owners are advised to do is put a piece of PVC pipe in the burgee holder forward to "test" the clearance."

I'm glad that other boaters have had a hard time measuring their mast height, but I really have no excuse when I think about it. I can climb to top fairly easily and its a straight verticle shot from the ring of the lightning protector down through the hatch to the main deck. Once I get that number it will only be matter of measuring the deck height off the water and that's fairly easy because of the stern door. Consider it almost done ;-)

Posted by: Ben E at April 17, 2013 3:58 PM | Reply

It's been a blast working up Chesapeake Bay and now I'm anchored in a creek near Annapolis very close to the home of PassageMaker founders Bill and Laurene Parlatore. They are very kindly hosting an "open boat" for Gizmo on their dock tomorrow afternoon and any Panbot in the vicinity is welcome. Email me (ben at panbo.com) for details.

Posted by: Ben E at April 17, 2013 7:53 PM | Reply

Leave a comment