BOAT SERIAL NUMBER

May 17, 2004
3,470
Beneteau Oceanis 37 LE Havre de Grace
XDY - It’s an O’day
N - An O’Day specific model name distinguisher, for an O’day 28 in this case.
0659 - Hull number 659 within that model.
The first 86 - Could this be “B6”? If so it was built in the second month (month B) of 1986.
The second 86 - Model year 1986.

Credit to O'Day Hull Number Reference Guide for having a handy decoder.
 
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May 17, 2004
3,470
Beneteau Oceanis 37 LE Havre de Grace
Also, if you’re not sure on 86 vs B6 based on the etching on the transom, the HIN should also be written elsewhere in a discrete place. If I remember right ours was inside the lazarette on the underside of the combing.
 
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Oct 22, 2014
16,100
CAL 35 Cruiser moored EVERETT WA
ON THE TRANSOM OF MY BOAT IS THE NUMBER XDYN06598686.
While that sounds perfectly logical what @Davidasailor26 said...

It also could be just gibberish that a boat worker came up with in the yard and stuck it where it could drive a boat owner crazy wondering what it means... For all we know it could be the release codes for a thermonuclear missile..

On the other hand David could be perfectly right. :yikes:
 
Oct 19, 2017
6,939
O'Day 19 Littleton, NH
From the O'Day Mariner Web site (Hull ID Help - Mariner Class Association).

"All boats manufactured or imported on or after November 1, 1972 must bear a Hull Identification Number (HIN)."

It was standard practice before '72 for many manufacturers to have a HIN, but there were variations in its form. If you know when your boat was built, it will be easier to decipher your HIN,

"Example #1: XDYF26040373
In this example XDY is the designation given to the O'Day company and F means it's a Mariner. 2604 is the sail number, the 0373 means the boat was built in March 1973."
-
Example #2:

"Here is an actual molded in serial from a 1978 boat.
Code XDY (O'Day), F (Mariner), 3627 (Sail Number), M (Spacer), 78 (Year) D (Nov. built)"

'M' = space. ¿Porque?

Key to Month of Model Year - Pre 1984.
AUGAFEBG
SEPBMARH
OCTCAPRI
NOVDMAYJ
DECEJUNK
JANFJULL
This chart seems illogical to me. Why randomize the order?

"Starting August 1, 1984 the letter designation for the month built next to the year built starts with A=Jan, B=Feb. etc."

"Boats manufactured or imported on or after August 1, 1984, also have a duplicate secondary HIN affixed somewhere on an unexposed location inside the boat or beneath a fitting or item of hardware. The purpose is to help authorities identify your boat if a thief or vandals remove or damage the primary HIN on the transom. It is illegal for anyone (manufacturer, dealer, distributor, or owner) to alter or remove a HIN without the express written authorization of the Commandant, U.S. Coast Guard."

Not to throw a monkey wrench into the issue, but it's possible your boat is a '68 built in September at a factory with the designation 6. O'Day had, at one time, several factories. I remember reading about the particular factory designation having made it into the HIN, but I can't find confirmation of that memory. The example above, of the ...M78D HIN is an unusual example where the month of manufacture is printed after the year. Or, the '8' in your number really is an '8' and 8686 means factory designation 8 in 1968 in June.

Here's my own HIN: Hull#: XDYF26320473. She is definately, by cabin style, a 1973.

Do you know the year your boat was built?

-Will (Dragonfly)
 
May 17, 2004
3,470
Beneteau Oceanis 37 LE Havre de Grace
This chart seems illogical to me. Why randomize the order?
Like cars, boats are often manufactured starting late in the year before their model year. Oday was probably on a schedule to start each model year in August, making that their “A” month.
 
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Aug 9, 2019
12
O’Day 28 Titusville, FL
XDY - It’s an O’day
N - An O’Day specific model name distinguisher, for an O’day 28 in this case.
0659 - Hull number 659 within that model.
The first 86 - Could this be “B6”? If so it was built in the second month (month B) of 1986.
The second 86 - Model year 1986.

Credit to O'Day Hull Number Reference Guide for having a handy decoder.
You were right, it’s a B not an 8. The problem I have is that the serial number for my boat is 0659. But O’Day stopped making the 28 in 1986. According to a couple of sources, only 507 were completed, so how could I be no. 659? Does the serial number correspond to the hull number? Beats me.
 
Oct 22, 2014
16,100
CAL 35 Cruiser moored EVERETT WA
Robert. Looking at this question I found the following link. Not sure about the number count discrepancy.
 
May 17, 2004
3,470
Beneteau Oceanis 37 LE Havre de Grace
You were right, it’s a B not an 8. The problem I have is that the serial number for my boat is 0659. But O’Day stopped making the 28 in 1986. According to a couple of sources, only 507 were completed, so how could I be no. 659? Does the serial number correspond to the hull number? Beats me.
Ours was serial number 0590 in 1985. It’s possible that hull number 1 was not serial number 1; I’ve heard of manufacturers skipping serial numbers before.
 
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Jun 2, 2004
1,839
Oday Day Sailer Wareham, MA
Like several other Boat builders, O'DAY actually had more than one Factory, although I'm not sure if the 28 was built anywhere other than the Fall River, MA plant. It appears that (based on other models) O'DAY may have issued "blocks" of Class#s (like 0659 on your boat) to each Factory and as that Factory built the boats they would assign Class#s in the order that they built them. Thus it is not impossible that Class# 659 was built, but maybe class# 565 was not built. My Day Sailer II is Class# 10201, but may or may not have actually been the 10201st DS built, since a block of Class#s were reserved several years prior to my boat being built (in December 1978) for a separate builder to use on the Day Sailer I boats that they built for the DSA.

It is also possible that the record stating that only 507 O'DAY 28s were built could have been in error?
 
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Jul 30, 2019
208
Seaward 25 777 Fort St. James
Ours was serial number 0590 in 1985. It’s possible that hull number 1 was not serial number 1; I’ve heard of manufacturers skipping serial numbers before.
So, if 0659 was an '86 and your 0590 is an '85, is it possible that O'Day had a convention of using final year digit, and that 59 and 90 were the actual serial numbers indicating that they were the Nth boats built that year?
 
May 17, 2004
3,470
Beneteau Oceanis 37 LE Havre de Grace
So, if 0659 was an '86 and your 0590 is an '85, is it possible that O'Day had a convention of using final year digit, and that 59 and 90 were the actual serial numbers indicating that they were the Nth boats built that year?
Sounds like a perfectly good guess.
 
Jun 2, 2004
1,839
Oday Day Sailer Wareham, MA
No, If the Class# (or serial #) is 0659, then this is the 659th O'DAY 28 built, or at least that is her official assigned Hull/Class/Serial Number (see my previous post about the possibility of different Factories using separate blocks of Class/Serial numbers). My DS II is Class# 10201 and she was built in December 1978 as a 1979 Model.
 

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Jun 2, 2004
1,839
Oday Day Sailer Wareham, MA
Key to Month of Model Year - Pre 1984.
AUGAFEBG
SEPBMARH
OCTCAPRI
NOVDMAYJ
DECEJUNK
JANFJULL
This chart seems illogical to me. Why randomize the order?



Not to throw a monkey wrench into the issue, but it's possible your boat is a '68 built in September at a factory with the designation 6. O'Day had, at one time, several factories. I remember reading about the particular factory designation having made it into the HIN, but I can't find confirmation of that memory. The example above, of the ...M78D HIN is an unusual example where the month of manufacture is printed after the year. Or, the '8' in your number really is an '8' and 8686 means factory designation 8 in 1968 in June.


-Will (Dragonfly)
I don't understand what you mean by "randomize the order" referring to the month code, MODEL YEAR ran from August to July, so the first, say 1982 model of a boat was at the time, built in August 1981, the last in July 1982. That is why the code letters are that way.

The original poster has a 1986 Model boat, can't be a 1968 because the 12-Digit HIN was not used until November 1972. Prior to that O'DAY used 2 Numbers to ID a boat, a HULL# and a CLASS#, Hull# referred to total O'DAY production, Class# referred to how many of that class. For instance, my 1970 O'DAY WIDGEON was Hull# 22698 Class# 1791, that means she was the 22698th boat built by or for O'DAY, and the 1791st Widgeon. My 1979 DS II has the HIN XDY10101M79E-D, which translates as XDY = O'DAY, 10201 = Class#, M79= 1979 Model Year, E = December (in this case, Dec 1978). The D = Day Sailer, it really should immeditely follow the XDY, but unfortunately, that wouldn't fit! <GRIN!> the USCG required HIN format had no provision for Class/Hull #s greater than 9999, so O'DAY had to add the Model Designation to the end with a dash. OOPS!
 
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