- Admiral Camara's squadron - at the same time that Cervera went to the West Indies, Camara was dispatched to the East Indies with the battleship Pelayo and the cruiser Carlos V. A redeployment to the West Indies was also possible.
- Italian Garibaldi class cruisers - The Italian firm Ansaldo built 9 sisters to the Cristobal Colon (with some variations in armament) and they served in 4 navies (Italian, Spanish, Argentine and Japanese). I have found vague references to the Armada buying a sister to the Colon to be named Blas de Leon.
- Princese de Asturias class cruisers - this class of 3 cruisers was under construction in Spain in 1898 but took over 10 years to complete. It's easy to speculate that an spurt of efficiency would have put these in service.
- Reina Regente class cruisers - another class of 3 ships. The lead ship was built in the UK, although considered a success she was lost in a storm. The next 2 were built in Spain and modified with a lighter armament to reduce top weight and improve speed. The redesign was a complete failure, and they were far to slow for fleet work. Alphonso XIII was in service but incomplete and left in Europe when Camara served. Her sister Lepanto was not in service at the time. Again, we need to speculate better efficiency in administration. Or we can assume that the Regente didn't sink (and thus there was no need for a rethink on design) and put a class of 3 ships under the original Clydebank design in service, or replace these with 3 Elswick cruisers.
- New Orleans class cruisers - The USS New Orleans and USS Albany were purchased on the stocks at Elswick in early 1898. Originally laid down for Brazil, these were up for grabs and the US bought them to prevent them falling into Spanish hands. Similar ships were built by the same firm for the Argentine, Chilean, Chinese, and Japanese navies. It easy to speculate these becoming available through political/financial crises and snapped up by Spain. These ships were small, but fast and well armed and ideal commerce raiders.
- Destroyers - the giant killer of the age, these were easy, cheap and quick to build and could in some cases be bought "off the rack" from Elswick, Thornycroft and Yarrow in the UK as well in France and Germany. The Armada had torpedo advocates and its easy to speculate that lobbying on their part would have the Armada acquiring some destroyers.
- Used battleships - at a slightly later date it become common for first line navies to sell off aging battleships to smaller nations. One might speculate that the French or Royal navies would be willing to do such a thing in the 1890s.
Ok so what would these give Cervera? On the surface, he would have a whole lot more of what he already had - armoured cruisers. Increasing his squadron would not change the result at Santiago, but operating a second squadron in the Antilles would change the scenario in his favour. The US fleet would need to split it's forces to cover more bases and therefore increase the opportunity for catching a US squadron at a disadvantage.
A larger destroyer arm would force the US navy to be more defensive in fear of torpedoes. This would affect not only battles but also the blockades (a night attack by destroyers on blockading squadron would make a great scenario).
In addition, a few smaller cruisers used in commerce raiding would really change the tone of the war. Now the US navy would have to really spread itself thin to protect commerce plus deal with a paranoid populace. Picture an Elswick cruiser on the Gulf Coast and another on the Eastern Seaboard, and possibly a third off California