Weight vs Power

[Clintonw_123]

Hello <br /><br />I am new to the board and will be buying a boat in the next three months. <br /><br />I have decided to purchase an older boat first to be sure my family and I enjoy it. My question is related to boat weight and power. I have read several topics on the board and the consensus seems to be to purchase the large engine 4.3 175 HP over the 3.0 130 HP for the newer boats and this makes sense, but I also noticed the newer boats 16-19ft all seem to weigh about or over 2000 pounds. I am looking at some older boats 78-85 and they all seem to weigh much less between 1000-1300 pounds. So it makes me wonder with weight of the boat being so much less would I still need 175HP and up or would 125-150 HP outboard be enough to use the boat for skiing with anywhere from 4-6 people in the boat.

 

[QC]

Re: Weight vs Power

Welcome to iboats Bill or do you prefer Billary? Kidding!! Couldn't help it . . .<br /><br />Don't trust any boat weights from anywhere other than a scale . . . My .02<br /><br />You are probably better off posting some specific examples you find and asking for opinions. Any 18ish bowrider thing will go really well with the 4.3s, but when you start comparing OBs, it gets tough because they weigh around 400 lbs less themselves. That I do trust . . . <br /><br />I used to ski behind a 1650 Bayliner (no cracks anybody, it wasn't mine) with an 85 Force OB. It got me (5'7" 150) out OK with 3-4 others in the boat, but it wasn't yanking my arms off by any means. I also owned a very light 17 footer with a 140 I/O and it was stronger and I towed it with a Toyota truck with a 4 cyl and manual trans. It was definitely not heavy, but I bet it still weighed well over 2000 lbs despite the spec sheet showing the hull at 850 . . .

 

[Texasmark]

Re: Weight vs Power

I had an 18' late 70's starcraft I/O aluminum with a 4 cyl 140 hp Mercruiser. The boat was much lighter than a comparable fiberglass and the engine pushed it along at a good clip....35 as I recall. But the bottom was plain Jane and nothing to get any real performance.<br /><br />Had a friend with an 18' '85 ish Searay deep vee with a 165 inline 6 cyl Mercruiser I/O that would run 45 easily. That boat was heavy but had lifting strakes on the bottom and the faster it went the more of the hull came out of the water reducing hull drag which allowed it to go even faster. Today we still have this type hull and some I/O's have a pad (like a waterski) upon which the boat rides when it is running flat out which really adds to the performance due to the extremely small wetted surface.....but you have to be going 40+ to get any real benefit out of that.<br /><br />On old weights vs new weights, can't say. Nowadays they are taking the wood out of the boat and replacing it with fiberglas (cause wood rots) which I think is heavier (more dense). That may account for the increased weight currently. Additionally, safety requriement may dictate more flotation. But that stuff is light so that wouldn't amount to much.<br /><br />Also, current amenities are probably much more pristeen than in the past and every added feature means more weight.<br /><br />Rule of thumb......<br /><br />On the water, you never have enough space (boat is too small) nor enough power.<br /><br />On land, the boat is always too big to handle and to tow.<br /><br />HTH.<br /><br />Mark

 

[Solittle]

Re: Weight vs Power

Lets see - 16-19' - 4-6 people - 125-150 hp - skiing - - -<br /><br />If you want to haul 6 people comfortably you will need to get a larget boat - 22-24'.<br /><br />You probably would not be satisfied with a 125 on a 19'er with 4 adults aboard.

 

[craze1cars]

Re: Weight vs Power

I need to echo SoLittle. I believe you will find that skiing with 4 to 6 people in the boat is going to take a boat bigger than the 16-19 ft range you're looking at. Everyone will be tripping all over each other, the skis, ropes, little duffle bags everyone seems to bring with, and of course the beer coolers! And then God forbid someone wants to bring a tube....yer done for! I just hope you all REALLY like each other 'cause otherwise grumpiness can take it's toll and ruin what was supposed to be a fun day on the water.<br /><br />I have a 1992 18 foot Rinker open bow runabout with a 3.0L I/O. I absolutely refuse to take any more than 4 people out (including me) if I'm skiing for all the problems I mentioned above, plus the horsepower issue....I've found with 3 on board and 1 on the rope, it is adequate to get my 190 lbs out of the water on a slalom ski, but just adequate. If I had 2 more people in the boat, I'm not sure it could get the job done at all without drowning me or ripping every muscle in my body in the process. I have it propped to the max already....it actually over-revs a bit at top speed. <br /><br />My next boat will be a MINIMUM 20 foot 4.3...no question about it...probably bigger. My advice would be to buy the biggest, most powerful boat you can possibly afford/tow/control safely. Most people who don't do it now will wish they had done it a year from now. But above all that, CONDITION trumps everything...ESPECIALLY when you're considering the vintage you're lookin at.

 

[Clintonw_123]

Re: Weight vs Power

I wanted to thank everyone for the input, I bought a boat last weekend and think it will work out pretty well. <br /><br />I purchased a 1979 18ft Glastron SSV-188 lots of room for an 18ft it has a Johnson 150 outboard, The boat is in really good condition inside and out the engine runs well 98-102 compression on all six cylinders and this was before we ran the motor that was still winterized. <br /><br />Paid $2500.00<br /><br />Thanks again

 

[studlymandingo]

Re: Weight vs Power

That'll probably do the job well. I have an 18' Center Console with a t-top, not a go-fast boat for sure. It has a 150HP Mariner on the back. It pulls me (195lb 6'4") up on a wakeboard pretty quickly with a 21" pitch prop. That's with another 3 people on board. I use the boat for getting offshore to fish also so the 21 gives me pretty good top-end. You might want to run a 19" pitch if you are mainly going to be skiing. Check your prop size before you go out. Note your WOT RPMs, speed and your hole-shot performance. Then when you get out of the water, go to the prop forum and see where you stand for your rig. Lots of great information there to help get the most out of your boat.<br /><br />BTW...Congrats on the new boat! Take a pic, and put it on the site!