Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Design > Sailboats
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 03-03-2004, 08:10 PM
Kaptin-Jer's Avatar
Kaptin-Jer Kaptin-Jer is offline
Semi-Pro
 
Join Date: Mar 2004
Rep: 206 Posts: 563
Location: South Florida
Adding full tramsom motor mount / dive platform

I have almost completed a total re build of a 27' Chrysler. Before it goes back in the water I am contemplating adding a full transom motor mount that will double as a dive platform. I will be doing a lot of sailing on the intercoastal water way and want to go to a larger motor (25- 30 hp). I would fill the inside of the transom mount with foam to off set the added weight. I have seen this system used succesfully on power boats, but never on a sail boat. Does any one have any experiance with a solid mount like this? It would be good to hear the negatives before I spend a lot of time and money.

Thanks
Reply With Quote
  #2  
Old 03-04-2004, 03:01 AM
PAR's Avatar
PAR PAR is offline
Yacht Designer & Builder
 
Join Date: Nov 2003
Rep: 2891 Posts: 8,798
Location: Eustis, FL
You would severely upset the balance of the boat, by doing this. A new 20 HP 2 stroke from Mercury will weigh in at about 110 pounds, a 4 stroke a bit more and the larger in size the heavier they'll be. No butt attached to the stern will fix this. The sailing performance will suffer a lot with her tail dragging like that. The weight isn't the real issue though.

You'll never use this much power anyway, your hull speed is in the 6.5 knot range and you'll only need a small kicker to get to this speed. To go much faster then that will cause the boat to become very unstable and could capsize (I've seen it happen in a sailboat being towed by a unwitting powerboat skipper who towed way to fast)

Have you ever noticed as you drive past a marina, that powerboats have very aggressive hull shapes? Sharp lines and angles sticking out everywhere? The sailboats have much smoother lines, easy, gentle curves, no hard angles or things jutting out? Ever notice this? There are exceptions to this, but there are many reasons power and sail have such different hull shapes and styles, and the two aren't interchangeable as a rule.

If you want a dive platform, buy a pontoon boat or other suitable craft for the purpose and hang the 130 pound 25 HP outboard on that. Though I have to admit it I had to fight not to tell you to go for it and let us know how it worked out, knowing it would be a real fun ride as you cranked up the motor to full scream and the boat started rolling and dancing. Right up to the point where it rolls over on her side and starts filling with water, it sure would be fun, kind-a-like riding a big inflatable hot dog shaped thing behind another boat. Yea, that kind of ride is fun, a little hard on equipment, but fun . . .
Reply With Quote
  #3  
Old 03-04-2004, 07:59 PM
Kaptin-Jer's Avatar
Kaptin-Jer Kaptin-Jer is offline
Semi-Pro
 
Join Date: Mar 2004
Rep: 206 Posts: 563
Location: South Florida
I guess you just saved me about $20,000.00

Thanks for your "wipping" -- I see the light! I knew there had to be a reason that I haven't seen this configuration. I'll stop trying to re-invent the wheel. I have spent a year putting real wood vaneer in the interior, replacing the molded fiberglass hatches with teak/ black plexi, awl-gripping, new hardware, new wireing, complete galley - you know the drill - a little jewel box. I wouldn't want to turn it into a rolling hot dog just for your amusment.

Thanks,
Kaptin-Jer

Quote:
Originally Posted by PAR
You would severely upset the balance of the boat, by doing this. A new 20 HP 2 stroke from Mercury will weigh in at about 110 pounds, a 4 stroke a bit more and the larger in size the heavier they'll be. No butt attached to the stern will fix this. The sailing performance will suffer a lot with her tail dragging like that. The weight isn't the real issue though.

You'll never use this much power anyway, your hull speed is in the 6.5 knot range and you'll only need a small kicker to get to this speed. To go much faster then that will cause the boat to become very unstable and could capsize (I've seen it happen in a sailboat being towed by a unwitting powerboat skipper who towed way to fast)

Have you ever noticed as you drive past a marina, that powerboats have very aggressive hull shapes? Sharp lines and angles sticking out everywhere? The sailboats have much smoother lines, easy, gentle curves, no hard angles or things jutting out? Ever notice this? There are exceptions to this, but there are many reasons power and sail have such different hull shapes and styles, and the two aren't interchangeable as a rule.

If you want a dive platform, buy a pontoon boat or other suitable craft for the purpose and hang the 130 pound 25 HP outboard on that. Though I have to admit it I had to fight not to tell you to go for it and let us know how it worked out, knowing it would be a real fun ride as you cranked up the motor to full scream and the boat started rolling and dancing. Right up to the point where it rolls over on her side and starts filling with water, it sure would be fun, kind-a-like riding a big inflatable hot dog shaped thing behind another boat. Yea, that kind of ride is fun, a little hard on equipment, but fun . . .
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hovercraft dive platform Moosen Boat Design 8 09-12-2005 06:49 PM


All times are GMT -5. The time now is 05:06 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net