It’s not clear to me that “armies” as referred to in the Constitution are required to be land forces, as opposed to a generic term for an armed military force.
The connotation that the military has divided commands based on how the troops are deployed is a modern misconception. Eighteenth century distinctions between the army and navy is based on how they were funded in England historically: levied troops provided by the gentry vs crown funds buying ships. The monarch was restricted by custom in how long troops could be levied. This is a source of the funding distinction seen in the US Constitution, not the conveyances of those troops.
Article I, Section 8, in part, says:
To define and punish Piracies and Felonies committed on the high Seas, and Offences against the Law of Nations;
To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;
To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;
To provide and maintain a Navy;
To make Rules for the Government and Regulation of the land and naval Forces;
To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;
It seems to say that, in general, armed forces (“Armies”) cannot be funded for more than two years at a time, except for a naval force (“Navy”). That is, there is a limitation on the funding the military, except for ships.
We do see a distinction between “Land” and “Water”, but that is about the rules of war, not the military forces themselves. And we see a distinction between “land” and “naval”, but that is about organization, not funding. I suppose a very literal interpretation would say Congress can fund the armies, but only organize ones based on land; I don’t find that very convincing. A better interpretation is that “land and naval” is a description of “Forces” and not a limitation on Congress’ power. The Constitution is a foundational document providing general guidance, not a law code with explicit rules, despite the some lawyers unable to grasp the difference.