Ball sizes

[HeadedToTexas]

We have only used traditional fenders to protect our boat, but the consensus is that ball fenders are superior in most ways, and particularly in locks. We are in the market for ball finders as we aspire to spend a lot of time in locks. Question is, what size?

The Mariner 37 (and Helmsman 38) hull begins its curve toward the bow right about in the middle of the length. We tie alongside a dock with padded posts which means the hull is 9 inches from the dock at rest. That same 9 inch distance is maintained from stern to the bottom of the steps leading to the flybridge. The railing offers convenient spots for hanging fenders at the bottom of the flybridge steps and again forward at the bottom of the steps leading to the bow, but the distance from the dock to the hull at that forward position is 20 inches.

Understanding that the posts won't be there in a lock or other such structures, would 12 inch balls in the two further aft locations be sufficient to allow compression and protection, and would a 24 inch ball be right for the forward location? What sizes do you guys use?

 

[rslifkin]

On my boat with a somewhat flared hull, I carry both 12" and 18" balls in addition to our 10" cylinder fenders. We use the cylinders most of the time as they're in nice covers and aren't as sensitive to height adjustment, plus they don't push the boat as far off the dock for easier boarding when the extra distance or cushion isn't needed. But when we need something bigger, or if we're in a lock or against a concrete wall we pull out the balls.

For locks, we typically use the 12" balls tucked up just below the gunwale and then an 18" ball forward and 1 aft just above the water (no need to adjust in a lock that fills close to the top and it'll keep the boat off a wall of any height even if the boat rolls a bit due to water flow in a lock or anything). In other scenarios we'll use the balls in whatever combo works best.

My hull has a similar curve (and the curve starts a little sooner at the waterline than at the deck, so flare increases towards the bow), but mine also tapers in slightly from the widest point to the stern. So just sizing fenders isn't the ideal way to get it to sit as desired against a dock, you end up having to pay attention to how lines are tied. Typically the 2 aft-most fenders are the ones with the most dock contact as that's the part of the boat that needs to be parallel to the dock for boarding (the centerline of our boat is typically pointed slightly away from the dock with everything positioned well).

 

[Comodave]

Go with the largest ones that you can store. You will come across situations that need bigger than you have imagined. I have never said that I wish my fenders were smaller but many times I have wished they were larger. We use the round fenders in locks but the cylinder fenders just about everywhere else.

 

[Mac2]

I found that a combination is best. Cylinders starting at the stern and round as you go forward (one or two), starting at the curve. I think you would want a 24 round near the bow. One lesson I learned going through the locks-those nice fender covers get torn up going through locks. They get pinched against the wall. If the wall goes up and down in the locks, not a big issue, but if the boat slides up and down against the wall in the locks, the covers get torn up.

 

[Comodave]

Yup, no fender covers in locks.

 

[Jeff F]

Go with the largest ones that you can store. You will come across situations that need bigger than you have imagined. I have never said that I wish my fenders were smaller but many times I have wished they were larger. We use the round fenders in locks but the cylinder fenders just about everywhere else.

Speaking of storage, balls can be pretty easily deflated for long-term storage. A bike pump and needle are handy for this.