Martin's chart of Syncro power vs. speeds was in metric units.
Many List members are more acoustomed to English units.
Here is a conversion of that table's values,
Plus a little bonus column of my own:

             (kW x 1.34)  (km/h / .621)
Speed  Power    Power        Speed      Tow cable
(km/h)  (kW)    (hp)         (mph)       (pounds)
  30      4      5.4         18.6         108.1
  40      6      8.0         24.9         121.2
  50      8     10.7         31.1         129.4
  60     10     13.4         37.3         134.8
  70     13     17.4         43.5         150.3
  80     16     21.6         49.7         163.0
  90     20     26.8         55.9         179.8
 100     23     30.8         62.1         186.0
 110     27     36.2         68.4         198.5

Looks like we need a LARGE inline fish scale to get to 80 mph.
Anyone willing to submit a data point of speed and tension?
Join the party.
1 hp = 33,000 lb-ft/minute
1 mph = 88 ft/minute
John