Several different makes and models of Outboards.
Deep narrow tunnel design.
https://www.youtube.com/watch?v=ZFyCVif2S60Before someone asks...how fast are they?
Here is a post from a fellow who knows.
Had one for almost 20 years. Merc 60, 75 stinger, V4 135, V6 235
steering very important as is motor height. Cut down the mids on the v4
& v6 ran much better with the V4 lower unit on the V6. But don't shift while running. Only steering that would work safely on V4 & V6 was hyd.
Motor height 1" above sponsons with all motas. Keep motas on transom for CG. Made tunnel tab and whale tail to get on plane easier with V4 & V6. 12 gal gas tank front and back for the longer trips. Threw the transom trim like tunnel boats. VERY important "DO NOT TURN BOAT" at speed! bigger the mota the worse it is. Still have my best prop for the V4 gear case it worked on the V6 also. Also still have a quicky lower that was 10mph faster vurses V4 lower.
Speeds
60hp-58mph
75hp-60-62mph
135hp-75mph V4 lower
135hp-85mph quicky
235hp-85mph V6 lower
235hp-92mph V4 lower
