Mold Marks:

A bottle which has no visible mold seam indicates that the bottle may have been Free Blown without a mold. These bottle will usually have an uneven shape can date to 1700s. Other bottles without visible mold seams could have been made with a dip mold or may have been spun in the mold to smooth out the seams. Spinning was a common practice when using wood molds. Note bottles spun in a mold are always round and can not be embossed. The only identifying marks are concentric lines that are found on the body and neck of the bottle..

When the bottles side mold seam ends below the top. This indicates the bottle was Blown in a Mold. These bottles will usually have a top that was applied after bottle was released from the mold.

When the bottle has three seem marks. One that runs completely around the circumference of the shoulder and two that run up the neck. This type of bottle was made in a 3 piece mold (3PM) and dates from 1820-1880. These bottle will usually have a crude hand applied lip.

By 1900 more precise tighter fitting molds were machined. These molds had vent holes bored into the molds shoulder. Usually found opposite the mold seams. Evidence of these vent holes can be seen as small uniform size dimples on a bottles shoulder.

When mold seem runs through top. Full height molds are called “Closed Molds” Indicates the bottle was machine made by a made by an Automatic Bottle Machine ABM. Earliest ABM bottle age to around 1903.

Hunting Antique Bottles in the Marine Environment.
By Capt. Dan Berg


Softcover, 5.5x8.5", 98 pages
printed in full color. $19.95 +P&H

Hunting Antique Bottles in the Marine Environment is the complete field guide for finding and identifying antique bottles. Capt. Berg has been searching for antique bottles in local lakes, rivers and on shipwrecks for over thirty years. Learn not only how to find submerged antique bottles but also how to clean them and how to determine how old they are. This text is packed with historical information that shows how bottles were produced and how each manufacturing process left distinct marks which can be used to accurately estimate any bottles age. Capt. Dan has heavily illustrated this text with over 200 color images depicting the types of bottles that can be recovered by searching local waters. He also uses over 10 unique 3D diagrams designed to give a better understanding as to the time line of glass blowing and bottle manufacturing. These 3D mold images are combined with drawings of the bottles they produced and highlight the distinct mold seam marks each created. This informative text tells all the tricks of the trade that until now have only been learned through years of experience. Bottle collectors, scuba divers and anyone interested in exploring the marine environment for these historic treasurers will reference this text often as they search for and collect antique bottles.


 Antique Bottle Identification Guide  Sample Pages


Sample Pages



This title is also available as a downloadable ebook
click here for details on all of Capt. Dan's downloadable products.


Hunting Antique Bottles in the Marine Environment.
By Capt. Dan Berg

Softcover, 5.5x8.5", 98 pages
printed in full color. $19.95 +P&H


This book is also available as a downloadable ebook

only $9.95
5.7 MB instant download, printable  PDF file





Hunting Antique Bottles
in the Marine Environment

Bottle Collecting
Bottle Characteristics
How bottles were made
Bottle Value
Bottle Types
  Screw Top
  Crown Top
  Blob Top
  Bromo seltza

  Black Glass

  Coca Cola
  Round and Torpedo
Water Hunting
  Scuba Diving
  Ferry Piers
  Dump Sites

Scuba Diving
Cleaning Bottles

Estimating Age
  Mold Marks
  Mold Mark Chart
Patent Numbers
Makers Marks
Just how old
Age Estimating Chart
Glossary of Terms

Scuba Equipment 
 Training Agencies
Equip Manufacturers






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