46 C.F.R. § 308.529 Surety Bond B, Form MA–309.
Title 46 - Shipping
An Assured who elects to substitute a surety bond for a collateral deposit fund shall submit Form MA–309, which may be obtained form the American War Risk Agency or MARAD.
Title 46: Shipping
PART 308—WAR RISK INSURANCE
Subpart F—War Risk Cargo Insurance
II—Open Policy War Risk Cargo Insurance
§ 308.529 Surety Bond B, Form MA–309.