Chelsa (Boston) Captain's Clock 1900-1904

Hello Juanita,
Thank you for sending in this Chelsea patented Time/Tide clock to mearto.com for an appraisal. I shall try to help you with that today. I decided not to wait for the photos once I recognized the clock.
TITLE:
Brass, steel and glass, battery operated quartz tuning fork movement, Time and Tide clock set into a wooden display holder, number 10….8….64 on rear of case, made by the Chelsea Clock Company, Boston, Massachusetts, USA, circa mid-1970s-early 1980s. Originally patented under the name ‘Sun and Moon clock in 1978.
PROVENANCE: From the estate of Dr. B. H. Crawford.
DESCRIPTION:
Case: 6” or 4.5” (size not provided) brass porthole ‘Tide teller’ model (Chelsea also made black phenolic or Bakelite Tide Mate). The façade of the brass case has a porthole look to the façade with a brass barrel cylindrical case and an expanding rear flange with holes for attaching to the bulkhead wall. {It is important to note that the need to keep significant lists of serial numbers and dates for Chelsea stopped after World War II, and the numbers and dates are far less specific after 1945. In addition, certain types of clocks including the tide clock, ship-striking and quartz clocks were not marked with serial numbers. Th numbers that I can see on the back of the case, 10…86…4, may in fact be a coded production date, perhaps from 1986 with month and day added.
Dial: Multi-colored round silk-screened aluminum dial enameled with an Arabic hour chapter ring, closed minute track with triangular markers placed every five minutes while the chapter ring is signed ‘Boston quartz’ over the 12 and ‘Chelsea Clock USA’ under the 6. The dial center in blue with Arabic numerals divided into two groups of numbers, 0-6, running clockwise and counterclockwise down from the twelve. Because of the equality of distance between the tide hours Chelsea suggested that this clock be used only on the East coast of North and South America and West coasts of Europe and Africa due to semi-diurnal, i.e., equally spaced high and low tides. High Tide is marked under the twelve and Low Tide marked over the six. Mid-Tide is marked @3 &9 along with ‘hours past high tide’ and ‘hours to high tide’. Red triangles are found at the quarters, large red pointer tidal hand points to the current tidal status. The clock has black steel Spade hands and sweep seconds pointer.
Movement: This should be an AA battery operated quartz tuning fork type movement. A Chelsea quartz movement combined a conventional timepiece with a centered symmetrical high and low tide indicator.
CONDITION:
Case – In very good condition and properly marked.
Dial – Some speckling around the periphery of the dial but fully legible and in very good condition.
Movement – Not seen but assumed as described, genuine and original to this case and fully functional.
Comments: Chelsea, I believe was the first to produce these. The first 2 years they had brushed silver dials. White dials after that. Tuning fork Accutron movement, no manual winding.
HISTORY:
In the mid-1970s, Jim Leone of Chelsea completed a prototype Time/Tide clock model. He began studying this deign in 1973. With some additional gearing his quartz clock could predict high and low tides on the eastern coasts of North and south America where tide cycles are relatively evenly spaced. He was granted a patent for this type of clock in 1975. In short order the German/English Schatz clock company and the Seth Thomas company followed with their own designs of time and tide clocks.
The Patent – Patent no 3,921,383, dated Nov. 25, 1975. Patent applied for by Anselm James Leone of Quincy, Mass. 10/10/1973.
“A first tide wheel is fixed to the hour hand tube of a conventional clock movement, above the fit-up cover. . . . . The Tide hand is frictionally carried on the Tide wheel bushing so it can be slipped for setting the correct indication…. A dial is provided on which the Tide hand indicts the hours to or from high tide, low tide and mid-tide.”.
COMPARABLES:
https://www.liveauctioneers.com/item/45976833_chelsea-tide-clock-in-wooden-holder ($40 in 2016)
https://www.liveauctioneers.com/item/80561073_chelsea-ships-tide-clock (sold for $250 in 2020)
https://www.liveauctioneers.com/item/84532646_chelsea-high-tidelow-tide-ships-clock (sold for $90 in 2020)
PRICING:
My impression is that the condition of the clock makes a difference in the price at auction, which is not surprising. I will assume that your example is at least in good to very good condition and I have assigned a fair market value to it in the range of $200-$225 with a retail value about twice that amount.
I hope this write-up has been of interest to you and that you have learned something about this tidal time clock. I found it of interest to do this appraisal. I guess it may be hard to test its tidal accuracy in Kansas City, but here in New Jersey one could really time the tides.
Thank you for choosing mearto.com for this interesting appraisal.
My best,
David

Dear Juanita,
Thank you for contacting Mearto with your appraisal inquiry. So that I may best assist you, can you please upload a few images of the entire clock so that I might at least see what it looks like. Please show me the sides and back as well. Can you also send me measurements of the width of both the case and the dial itself.
With appreciation,
David