How is the length of a boat determined?

I have a Bayliner Trophy boat that says 21 ft on the registration but from the back to the front not counting dive platform or outdrive it's about 24 ft. what's right?

Re: How is the length of a boat determined?

Don't curve the measuring tape around the bow. The tape needs to go in a straight line. If you curve the tape, you add length.

Sometimes a measurement includes things beyond the transom, such as integrated swim platforms. That can add a couple of feet.

Typically, a straight-line measurement from bow to stern... but the stern is sometimes different to different people. The builder often names the boat along the lines of it's approximate measurement. "Trophy 213" might be a 21.3 foot boat.

I have a Scarab 26 that measures 26.9' from bow to stern (but my stern is the end of the integrated swim platform).

When registering and paying for things by the foot, you have a 21' boat. When buying things, like cover or trailers, you have a 24' boat.

link about how Bayliner does it: http://www.ehow.com/how-does_4928737_bayliner-measure-boat-length.html

Re: How is the length of a boat determined?

Boats are measured differently now than in the past. There might be a lot of measurements taken from a boat. I have always HATED when a boat is called a certain length, and it includes the platform and pulpit. Even if they are intergral, I feel it gives a false impression of the boats size.

My boats called a 297 or 29'er.

My boats length is 28'8", which is measure from the transom to the point of the bow. With the bow pulpit (integral) it is 32'4". With the platform (not integral, but standard equipment) it measures around 34'4". I like the fact my boat is considered a 29'er, because to me it is. A new version of this boat would probably have an intergral platform and be called a 32'-33' boat.

There are others ways for boat measuring, LWL (length at the waterline), LOA (Length overall, to include anything on the boat) etc...

But I like the boats that measure 29' from bow point to transom and are called a 29' boat.

Re: How is the length of a boat determined?

Philster said:

When registering and paying for things by the foot, you have a 21' boat. When buying things, like cover or trailers, you have a 24' boat.

Click to expand...

Also to note on this point, when looking for a slip, double check the policy. My 29' boat, at some marinas, requires a 35' long slip.

Re: How is the length of a boat determined?

25thmustang said:

Also to note on this point, when looking for a slip, double check the policy. My 29' boat, at some marinas, requires a 35' long slip.

Click to expand...

Exactly. Slips require you measure from the tip of the bow (including the anchor if their is one) to the very end of everything on the boat, including outdrive while tilted up. My 21 foot is actually considered 24' at the slip.

Re: How is the length of a boat determined?

I had always been told there was no real standard in measuring a boat. The manufacturer would measure what he that it should be.

My boat is titled a 2100VBR, 21'. Without the trailer, it measures 24' 2". Go figure that one. And I don't have an bow pulpit or extra swim platform. Just the one molded into the boat. Oh, and if I add the outdrive I get another 7".

If I measure from the backrest in the bow to the rear of the sun deck I get 21' 3".

Re: How is the length of a boat determined?

Here is a good one.

My dad has a 1979 I believe, Hydrasports bow rider. The boat model is called a Playmate 150. It is an 18' boat, reg'd as an 18' boat, but the model number was a 150. I think it is called that, due to the that being the max engine size (I heard rumors the 16'er was called a 120, for the same reason), but find it ironic.

http://www.nadaguides.com/default.a...y=1981&ml=H&z=06450&gc=MR&gtc=MR&d=1600091336

Re: How is the length of a boat determined?

Some/most manufacturers have used the measurements from the "usable" part of the boat (hull length). This would be, in my specific example, from the pointed portion of the bow to the transom. Hence my Carver 374 is a 37' boat and the "4" is part of the model number (convertible), whereas another number (372 for example) might mean a 37' hull with an express-style cap.

I haven't seen any boat where the numbers indicated feet & inches (244=24' 4"). Most often, the model are hull length and design.

However, measuring my boat from the tip of the bow pulpit to the rear of the swim platform gives me a 40' LOA. I can use this measurement to impress girls...much like adding inches to other things to impress girls

Luckily, my marina charges off of the listed hull length, thereby saving me roughly $25 per month.

If you want an accurate length of your boat, run a tape down the centerline from the tip of the hull to the transom (then add 2' to impress the girls ).

Re: How is the length of a boat determined?

Naval architects generally go from transom to bow, and don't include pulpit or swim platforms. Mfrs. will typically include everything so that the boat sounds much more impressive and can command a higher price tag.

A lot of these boats would be/sound a lot less impressive if they were marketed by their LWL (length at the water line), which is a much better measure of a boat's performance.

Where it gets tricky is if you have a 19.5-foot boat with a swim platform and/or pulpit that makes it, say, a 22-footer. This can be important when it comes to certain regulations (different for boats over 20' vs. under 20'). Same goes for boats over/under 26'. Likely the CG and your insurance company will have the final say-so on how long your boat is - maybe they have standards (hopefully the same!) that they go by.

Re: How is the length of a boat determined?

The ONLY standard is LOA-length over all. Simply put, if you parked it between two walls, what would be the minimum distance be between those two walls. As someone else mentioned, this includes ANYTHING attached to your boat, including anchors or even tilted outdrives.

Sometimes manufacturers REALLY fudge those numbers. You see that a lot in the 15.5/15.9 classifications. Because additional regulations and cost kick in at 16 feet and longer, they used to slide a lot of boats in just under. I had an official 15.9' trihull that was at least 17 feet of actual hull.

Re: How is the length of a boat determined?

Here is a good example. A couple years back I found an ad for a 27' Sea Ray Sundancer. I was interested and got in contact with the owner. I had one small photo of the boat to work with. The 27' Sundancer is a 10' beam, usually twin engine boat. After discussions with the owner, and doing more research into the photo, I found the boat was actually a 25' Sundancer. HUGE difference. 8.5' Beam, vs 10', sleeps 4 with a Vberth and smaller aft cabin, vs having a larger dinette and sleeping 6...

It really was annoying, as he advertised this as a 27' boat, when it was not.

Re: How is the length of a boat determined?

We measure our boats from bow to stern, down the center of the boat not including any bolt on items i.e. swim platform, bow pulpit. It has to be part of the molded hull. BAYLINER/TROPHY CUSTOMER SERVICE TEAM

Re: How is the length of a boat determined?

BCS is exactly correct. Per NMMA/ABYC regs, any bolted on portion of the hull, such as pulpits, swim platforms, or engine brackets, cannot be counted towards LOA. However, molded in pulpits and integrated swim platforms can but not always are. Understating the LOA of the boat (which is allowed if it's over 20') gives the manufacturer leeway to produce a 24 one year, change the model number, and next year it's a 25. Boats grow by decals...

Re: How is the length of a boat determined?

Bayliner Customer Service said:

We measure our boats from bow to stern, down the center of the boat not including any bolt on items i.e. swim platform, bow pulpit. It has to be part of the molded hull. BAYLINER/TROPHY CUSTOMER SERVICE TEAM

Click to expand...

WOW, how's that for an informed answer.

Straight from the horses mouth. I'm impressed!