Who's Here?

[READY2GO]

All this talk of size lately got me to thinking maybe a poll of boat displacement might be interesting. So let's see who we are. Please enter your boat into the poll.

 

[MurrayM]

Hi there,

Edit: never mind, I see it now...

 

[Cyclone]

Greetings: Now that this poll has been initiated, why not ask a couple of other questions. Age of boat, years of ownership and of course Age of Captain. It would establish an interesting set facts. Bill

 

[twiisted71]

'83 Mainship Mk III with 6.354 Turbo,intercooled, aftercooled, manicooled, GPH verycool!!!

 

[Captain K]

Marine Trader 44, 32,000 displacement, 1978 vintage. Captain 1947 vintage. Had the boat for 3 years now.

 

[LarryBud49]

Marine Trader 34, 17,000 displacement, 1988 vintage. Captain 1949 vintage.

 

[Pau Hana]

1989 PT-52 Yachtfisher, 70k displacement, skipper of the birth class of 1963, 30+ years experience.

 

[chc]

1984 Californian 34 LRC, 18000# displacement, 1941 Captain, 7+ years ownership

 

[RT Firefly]

Greetings,
Oh no ya don't.....Other than I'm 434 in dog years and feel every one of them some mornings.

 

[Cyclone]

Well, the flood gates have opened and isn't interesting. Having started the game, me, from Oct 1976 until Sept 2012 a 1963 36 aft cabin single screw steel Goodraugh, built at Wheatley Ontario, Now the proad owner of a 1987 CC Catalina 381. ( I know she is not a trawler, but placed with the trawler fleet of semi displacement hulls, she fits right in picture) Now to the question, DOB, well my history in boating started in 1937. Bill

 

[Cyclone]

Groucho: Get with it we all know that you sit on the right hand, but nevertheless letting it all hang out will enhance your following. Bill

 

[RT Firefly]

Greetings,
Ah, Mr. Cyclone. I don't know about the right hand and if I let it all hang out, I do know for a FACT I'll attract every legal female in the tri-state area and I'm getting too old to put up much of a defense to fight them all off. I will say I used to be a blonde haired blue eyed fellow of viking ancestry (hence my love of the sea) but now-a-days more of a white haired bleary eyed rapscallion.
That's ALL you're getting out of me.

 

[Gulfstar 36]

How do you determine this number?

 

[Blue Heron]

26,000 lbs 1985 Nova Heritage East
Bringing up the lower end of the bell curve as I was born the same year as the moon landing.
New Skipper.

 

[Marin]

How do you determine this number?

If you are referring to the weight of your boat, sometimes the information will be in the owner's manual although it will be an as-delivered weight with no owner-added equipment included. And if the boat was available with one or two engines, like most GB models, for example, that has to be taken into account.

But most of the time we get the weight of our boats from the Travelift operators when we haul out. Travelifts (and I assume other haulout equipment) have scales on their slings. So in a typical dual-sling rig the operator reads the load on each sling and adds them together to get the total weight of the boat.

 

[Blue Heron]

I would also recommend you check the document number on your certificate or abstract.

 

[MurrayM]

Am I right in understanding that 'displacement' is the weight it would take to make a boat sit on its lines, as the designer intended?

If that's the case, I voted wrong because the manufacturer of our 30' Sundowner Tug lists its displacement as 9,600 lbs. I voted 10,000 to 20,000 because all the ones I saw on boat hauling advertisements had them around 15,000 lbs.

Why are there no straight forward answers when it comes to boats?!!?

 

[Marin]

If that's the case, I voted wrong because the manufacturer of our 30' Sundowner Tug lists its displacement as 9,600 lbs. I voted 10,000 to 20,000 because all the ones I saw on boat hauling advertisements had them around 15,000 lbs.

I don't think you voted wrong. The poll came about as a result of the discussion about get-home-outboard motors. Some people believe that a 10 hp or so motor will suffice while others felt that for larger, heavier, and higher windage boats an outboard of this size would be pretty much worthless as a get-home motor.

So I think the number that's really relevant to the issue is what does your boat weigh as you use it today, not as it was built x-years ago.

 

[Jolly Time]

Cyclone, I think we have the same hull? My neighbor has a 381 Catalina and minus the aft cabin they look identical. Chris Craft bought the Uniflite molds when they went bankrupt and used them on several Catalinas and even a few Commanders!! 25000#, 1976 Uniflite SS, First Year as Owner/Restorer, 1967 DOB.

 

[JAT]

79' GulfStar MC... 44', twin Perkins....me...old...vintage 50'.

 

[READY2GO]

Wow, interesting poll so far.

1978 Marine Trader 36. We bought her 9 months ago, was a rag bagger before that. We like the change. Although I am 53 I am not near as old as my kids think I am.

 

[DonnyP]

1983 Cheer Men PT 41, 28,000 lbs. Captain 1978 vintage, 10 yrs experience on pops boat. This is my first boat and just finished first season, itching fog spring!

 

[xfedex]

All this talk of size lately got me to thinking maybe a poll of boat displacement might be interesting. So let's see who we are. Please enter your boat into the poll.

Displacement and weight are not the same are they? Weight is measured in the slings on a lift. Displacement is the weight of water that the vessel displaces. Is that right? Anyway we weigh about 40000 lbs. 1998 boat. 1947 skipper. Got the boat 4months after initial launch.

 

[millennium]

I always thought displacement and weight were equal. I could be wrong.

2000 Mainship 390 with twin Yanmar. 26000 pounds. 55.

 

[Marin]

I always thought displacement and weight were equal. I could be wrong.

2000 Mainship 390 with twin Yanmar. 26000 pounds. 55.

So did I. Our boat weighs about 30,000 pounds. So it sinks into the water until the hull displaces 30,000 pounds of water, at which point it stops sinking into the water and floats. Add weight to the boat like a person stepping aboard and it sinks deeper into the water until the amount of extra weight is displaced at which point the boat stops sinking again and floats.

That's how I've always understood it to work.

 

[markpierce]

"A ship's displacement or displacement tonnage is the weight of the water that a ship displaces when it is floating with its fuel tanks full and all stores aboard. The term is usually applied to naval vessels. Displacement is the actual weight of the ship, since a floating body displaces its own weight in water. Another way of thinking about displacement is the weight of the water that would spill out of a completely filled container were the ship to be placed into it." (Thank you, wikipedia.)

On the other hand, tonnage is a measure of volume for non-military craft.

 

[GFC]

95 model Sea Ray, 65,000 pound displacement when loaded. Me? I'm a 1946 model and I got my first boat at age 5. You do the math to figure the years of experience.

 

[Northern Spy]

Any object floating at rest in still water will displace a volume of water which weighs exactly the same as the object.

However, "Displacement" as stated by the designer is computed from volumetric measurements at specific waterlines.

Tonnage is a measure of volume, and specifies the usable cargo volume of a vessel.

 

[ARoss]

Marine trader 34, '73 vintage, Captain 1942 vintage. The specs on the boat are 17,000 # but I would guess most of our MT34's are close to 20k with all the stuff that's been accumulated aboard over the years.

 

[baldpaul]

52,000lbs, 2005 49' Defever RPH, 2yrs in May....went from 20 footer. My vintage is 1967, a Centennial year in Canada.