This article covers best practice in order to transport your Hydrofoiler XE-1 battery via plane.
Yes, Manta5's Hydrofoiler XE-1 batteries are certified to be flown and can fly via cargo plane only. Batteries must be charged to around 30% in order to be shipped/ flown and thoroughly checked to ensure they have no faults.
Like with all lithium-ion batteries, you may likely have to declare the batteries as they are considered dangerous goods (DG) and this is common practice. You may also have to fill out any necessary travel forms or documents as required by the carrier/ airline in order to have these flown.
Manta5 recommends that you reach out to the airline/ carrier directly in order to determine what you must comply with regarding rules and regulations with your region/ country(ies) when seeking to travel with batteries.
Battery specifications and certification sheets can be found here.