It is critical that the information and dimensions that are provided regarding the boat be accurate when requesting a quote. The boat needs to be measured to double check the manufacturer's information in the owner's manual. The following will give the basics as to how to go about obtaining the measurements.
Overall Boat Length measurement should be measured from the tip of the bow to the centermost part of the stern. This would be from the most aft fixed appendage attached to the boat to the forward most fixed appendage of the bow or bow pulpit. Include in your measurements bow pulpits, stern rails, swim platforms, motor brackets and the length of motors or outdrives in the raised position. If the boat is on a trailer, measure from the tip of the tongue to the end of the motor.
Total Height is measured from the bottom of the keel to the highest non-removable part of the boat. The typical bridge clearance in the USA is 13'6" to 14'. Boats with an overall height greater than 13'6" loaded on the trailer require special handling and routing. It is therefore critical that this measurement is accurate. The draft which is the distance from the bottom of the keel to the waterline plus from the waterline to the highest part of the vessel equal the standing height. If the boat has for example a flybridge, it may be necessary to obtain the height without the bridge to determine if its removal is necessary.
Beam is the overall width and is measured as the widest point of the boat including the rubrail and anything attached to the boat. Boats that are greater than 8'6" wide are regarded as oversized vessels and require state permits for oversized loads. Boats that have a beam of greater than 12' will require a certified escort which will also add to the transport costs.