Ebay offers Altama Men's OTB Maritime Assault Mid Tactical Boots for $39.98 (reg $119.99) with free shipping.

Product Description:
Designed specifically for U.S. Navy Seals, the Altama  Men's OTB Maritime Assault Mid boot fits inside military dive fins. This amphibious boot is also designed for wet environments and features drainage vents on both the instep and outstep. Fast drying Cordura panels and a full rubber insole ensure you won't get slowed down by sloshy boots. This boot is designed for tough duty and features a high abrasion toe to prevent scrapes and cuts scrapes. A lightweight one piece ABS shank provides stability and support to reduce fatigue. A great choice for training or operations, the Altama Men's OTB Maritime Assault Mid is a great choice for professionals looking for low-profile footwear made specifically for maritime environments.
Features:

• Men's Maritime Assault Boot for all tactical water operations
• Mid 4 inch height
• Multicam Upper
• Air mesh linings help wick away sweat and other moisture
• Full length one piece ABS shank provides stability and support
• Non-shine rust-proof lace hardware
• Ultron PU contoured insole will not absorb water
• High abrasion quick drying 1000D Cordura quarter panels
• Front non-metallic drain ports allow for water to drain easily
• 13.5 oz (383 gr)