Measuring a Bimini Top
The only thing you need to do before ordering the biminitop is to choose the length, height, and width of the biminitop that best fits the size of your boat.
The length (L) and height (H) determine how much shade your biminitop will provide.
Decide where the biminitop will be attached and what the reach of the top is when you unfold it. Also, check where the top will be in the lowered position at the back of the boat. Make sure there is enough space at the front and back of the biminitop to mount the attachment eyes on the boat, where the straps of the biminitop will be fastened.
Using a measuring tape, you can determine which length of the biminitop provides the desired amount of shade on your boat.
The main mounting point is approximately in the middle of the biminitop on both sides of the boat.
After you have determined where the biminitop will be attached to the boat, measure the distance between these attachment points to determine the width (B) of the top you need.
The frame is adjustable in width so it can be mounted within the specified range indicated in the sizing when you order the biminitop. (see image above)
Example of a width size of 155-169 cm: This means that the biminitop is generally 155 cm wide but can be mounted up to a width of 169 cm. There is an adjustment range of +/- 15 cm. For stability, it is better to set the bottom of the biminitop outward rather than inward, but both are possible!
Choose the width that most closely matches your measurement of the distance between the attachments.
Height
You determine the correct height while standing in the boat by measuring straight up from the attachment points to the desired height. You and any passengers should be able to stand comfortably on larger boats. If you are mounting the biminitop on a small boat, do not go too high; if you can just stand with a slightly bent head and knees, that is sufficient. The higher you go, the less shade you get. Especially on small rubber boats or fishing boats, you usually sit and there is no room to move your seat if it is in the sun. If you can stand slightly bent under the biminitop on such boats, that is actually good enough.
Additional information for sailboats
Pay close attention with sailboats because there are more factors to consider. Ask yourself when you will use the biminitop. If you want to use the biminitop while sailing and the boom hangs above the biminitop, keep in mind that when you hoist the sail, you usually lower the crane line. This causes the boom to hang lower, and especially when sailing close-hauled with the mainsheet tight, the boom usually comes even lower.
It is also useful to consider the mounting location. Sailboats often have a raised cockpit edge. If you place the biminitop on the cockpit edge, it can significantly limit movement because there is a frame in the way. Usually, but not always, it is more practical to place the biminitop on the outer edge of the deck so you can always walk forward.
You may also need to consider the backstay or double backstay. Often you place the biminitop in front of this stay, but sometimes that is inconvenient. We can also make a two-way zipper in the middle of the biminitop between the tubes, allowing you to create more shade. If you have two stays, that is also possible, but you must measure very precisely how far apart these stays are at the highest point of the biminitop.