In the years prior to 1898 the US Coastguard was the major, abiet unintentional, force stopping insurrectional landings in Cuba. The follow citation is from French Ensor Chadwick. Chadwick was Rear-Admiral U.S. Navy when this was written (1909), however, during the war, Chadwick was the commanding officer of the USS NEW YORK, the flagship of Admiral Sampson. Unless otherwise noted, data in brackets is from Larry Daley, the contributor of this information)
"...Expeditions landed with scarcely an attempt on the part of Spanish cruisers or garrisons. With proper energy, with 67 [Spanish] vessels of all classes in Cuba, and with more than 200,000 men [Spanish military personnel] available on land, the coast should have been securely guarded and every landing-place made impossible to an invader. Instead the Cuban [Spanish military] authorities leaned almost wholly upon the American government for prevention, there being but one seizure afloat by the Spanish, that of the [ship] Competitor, during the three years of the insurrection.
Of the 71 expeditions of which there is report, but 5 were stopped on the coast of Cuba by the Spanish. The United States authorities stopped 33, the English 2; 4 were prevented by storms; 27 were successful. Nearly all the vessels were but small tugs of less than 100 tons. Only 4 were larger ships: the American [ship] Laurada of 899 net tons; the English [ship] Bermuda of 823; the Norwegian [ship] Leon of 490, and the Danish [ship] Horsa of 459. The responsibility for the last three rested largely with the consuls of the nations to which they belonged, as they could not have left American ports with their [the consuls' permission]. The Bermuda made 5 trips, the Horsa 2, the Three Friends, a tug of 89 tons, made 8, the Dauntless, of 77 tons made 12.
Said the secretary of the treasury [footnoted in citation to 'Letter
of the secretary of the Treasury, November 30, 1897. House Doc. 326, 55
Cong., 2 Sess., 10 and 18], speaking of an expedition by the Laurada, in
February, 1987: "If the Spanish patrol of 2,200 miles of Cuban coast had
frustrated one-half the number of expeditions that were frustrated by the
United States authorities along a coast-line of 5,470 miles, not one man
nor one cartridge would have been illicitly landed in Cuban from the United
States in the past two years and a half. In this particular instance the
vessel landed men and arms unmolested for two days in a prominent sea port
(Banes author's note), though all Cuban seaports have been reported under
Spanish control, though the Spanish authorities had been informed of her
landing and even minutely of the situation of torpedoes (now known as mines)
which had been laid for her (the Laurada) protection."
Chadwick, French Ensor The relations of the United States and Spain. Diplomacy. (New York: Charles Scriber's Sons, 1909), p. 418.