These are two axis torpedo boats used in the Mediterranean and surroundings. The Schnellboot S-151 class was going to be completed in Holland to a British design, but the captured unfinished boats were completed as small S-boats able to navigate inland to the Mediterranean. Compared to the later S-Boats these measured only 28.3 m in contrast to 35 m. Very little information about this interesting class is available. The other boat is an Italian MAS-500 (Motoscafo Armato Silurante = Torpedo Armed Motorboat). The Italian showed the power of such small boats during World War I. The design evolved during the inter war years benefiting from the Isotta Fraschini engines, which also were sought for the earlier British MTBs. Their length was 18,7 m and even less information was available for this type. These are scratch card models in 1/400 with some photo-etched and wire details.
Main references were:
http://www.prinzeugen.com/SBOATIND.htm
and the Squadron Signal Schnellboot in Action
for the MAS isolated googled images