I am looking at a 66' Symbol, 18'6" beam, 4'8" draft and a weight of 111,000#. I've been told at WOT the port engine is 2289 RPM, boost 33# and a 100% load. The SB engine is 2268 RPM, boost 34# and a 100% load. At WOT the speed is 19.5 knots. Props are Faster Nibral 4 blade 38" x 44". The gear ratio is 2.636 to 1. At 2000 RPM it supposedly does 15.5 knots. It has Cat 3406E engines rated at 800 HP. The props have not been scanned and I do not know anything else about their condition. I've been told that the performance should be 18 knots at 2000 and 21 knots at WOT in excess of 2300 RPM Should this boat do 18 and 21 knots?
There was a recent post by an owner of a Symbol which I believe is a 66. Perhaps he can answer your questions. http://www.yachtforums.com/forums/symbol-yacht/12740-symbol-yachts.html Judy
Exactly which model Symbol is it? I have a 63 Symbol Classic which Symbol then decided to call a 61 and now call it a 66!! Are you looking at a new boat?
Is it a new boat or second hand? If second had what year? Do you have a link or further information on the exact boat?
Assuming that the vessel turned 2300 rpm's new, you either lost horsepower from the engines, gained more drag whether it be air drag (enclosure etc) or water drag, or the vessel got heavier. I would guess it's the last one and I see a lot of yachts lose RPM's over the years due to the hull gaining weight and additional equipment being added to it.
Water intrusion Hi Capt. James, Would water intrusion into the hull areas that are not solid fibreglass also mean the secondhand/newer construct boats will not perform anywhere near original factory specs? Whenever my boats have been lifted for anti-foul etc, the weight is shown. Give or take additions, which can be many & numerous, could this be a reasonable way to tell the hull integrity of a second hand boat with cored etc construct? Especially as when buying a boat the former owner would unload most his "additions" leaving items such as tenders etc that can be removed for the exercise?
It's possible to find water intrusion, but you'd have to know that boat and what additions it's gained since the last haul out.......but not a real way to find water intrusion by weighing it......you're much better having a survey with a thermal imaging camera. Another thing to consider, is think about how many layers of bottom paint there are......Ever lift up a can of bottom paint, then multiply that by how many gallons go on the bottom each year. I had one boat with probably 9-10 years of bottom paint on it.......soda blasted......and re-bottom painted..... it picked up 1.5 knots....(20 knot boat). and the bottom was clean and speeds were recorded before and after
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