Originally Posted by saltysenior
again i bring up the question of these so called ''tests''......where were they run???? i'll run a boat in 10 feet of water and come up w/figures that will make a sister ship running in 90feet look like a dog...
MTU & Caterpillar require there surveys for extended warranties to be carried out in at least 95 feet of water.
a 50 post with Cat's will not run in Lake Worth buts runs like a scalded cat at sea in deep water.
Same with any Hatteras SF, they need deep water. Try running a 77 in shallower water and watch for the submarine effect, take it deep sea and it will run but do it in an enclosed bridge as anything more than 3 footers and you will get soaked.
Of course current has a huge effect on the speed, the current off Port Everglades can vary from zero up to 3 knots and some times is close to shore and other times well offshore.
The university has monitoring equipment that tells exactly the strength of, direction and position of the eddies but nobody wants to pay for the info'.
Always run in opposite directions when doing any tests and position the tabs for optimum performance. Do the runs in exactly the same tracks, not 1/2 or a mile apart as the current can be different.
An older Hatteras motor yacht with Detriots can loose 5 to 8 knots with just a few barnacles on each blade no matter how deep the water.
A 50 Viking express looses 80 RPM's and 3 knots with no tabs.
The old water jets on the Sunseekers had to be spotless to get it out of the hole, Denships need special props and tabs to make them run.
Fuel burn, % load will vary due to air & water temp. with different readings between summer in South Florida & winter up North.