1. On 12 May, she sighted two periscopes and opened gunfire on I-31 who dived quickly but not before Frazier had scored hits on the periscopes.

2. The driver looked through three M27 day periscopes, one of which could be replaced by a night vision periscope.

3. During World War II both Allied and Axis forces used acrylic glass for submarine periscopes and aircraft windshields, canopies, and gun turrets.

4. In periscopes with many Apochromat relay lenses, availability of lens blanks with the required refractive index homogeneity and constancy in value from one lens blank to another, can dictate the need for melt data redesign

5. If direct visibility abaft is restricted during the voyage, this lack of visibility may be compensated for during passage by the use of flat reflector periscopes or radar apparatus; the antenna of the radar apparatus shall be placed in the bow of the vessel.”

6. Given the complexity involved in setting up and using periscopes with flat reflectors for looking to stern, and also the fact that, with modern radar equipment, the necessary observations can be made from the wheelhouse, we propose that the second sentence of article # as set out in # dd # should be amended to read, after the words “visibility abaft is restricted during the voyage”, as follows: “..., this lack of visibility may be compensated for by the use of radar apparatus”

7. Given the complexity involved in setting up and using periscopes with flat reflectors for looking to stern, and also the fact that, with modern radar equipment, the necessary observations can be made from the wheelhouse, we propose that the second sentence of article 1.07 (2) as set out in TRANS/SC.3/WP.3/2002/21/Add.1 should be amended to read, after the words “visibility abaft is restricted during the voyage”, as follows: “..., this lack of visibility may be compensated for by the use of radar apparatus”.