Ukraine's homemade sea drones often fail, but they're so cheap that it doesn't matter, expert says

• Ukraine's likely sinking of the Ivanovets shows the advantage of sea drones.
• Russia has destroyed many of them, one expert said — but they're cheap enough that it doesn't matter.
• The sea drones also have a longer reach than more expensive cruise missiles, he said.

Ukraine's home-developed naval drones are offering vital capabilities that cruise missiles just don't have, a naval expert told Business Insider.