Tue. Apr 16th, 2024
Mast Float

In this article you’ll learn how to make a DIY mast float using just a milk bottle, rope, and some tape. In a strong breeze having one may actually give you an advantage. They may not be the most aerodynamic of objects but there effect on your speed would be minuscule in strong winds. And they have the big advantage that you avoiding wasting ages turtled or with your mast stuck in the mud.

What you need:

  • 3L+ Milk bottle
  • Electrical tape
  • 1 foot of rope


  1. So once you’ve got your bottle give it a wash out. I left my milk bottle for a week and it didn’t smell too good afterwards. so make sure to give it a good wash before you use it.
  2. Put the lid on tightly and wrap some electrical tape around it to make it more watertight.
  3. Tie a bowline around the bottle handle. Attach the other end to the eyelet in the head of the sail.

So time to put it to the test. Note this is just 3.5L compared to the roughly 10L of most other mast floats so it would be interesting to see how it did.

I capsized the boat on the jetty and at first it seemed to be proving up to the task. But it was lying lower in the water than I’d have liked. The Solo mast is relatively heavy compared to other dinghies so although 1 3L bottle should be fine for holding it while you right the boat I thought I’d check to see the difference 2 3L bottles made.

Luckily, I had another bottle which used to hold hand soap. I attacked this to the milk bottle with the rope running through the eye of the sail. The problem with timing it like this is if 1 bowline comes undone you’ll lose both mast floats. So a better way to do it would be to tie them each separately to the eyelet.

2 bottles made a notable difference. They were able to hold the mast high in the water for a prolonged period. So, if safety is your main goal I’d recommend using two bottles. If you just want to get the boat up from a capsize earlier 1 should be sufficient.

Crewsaver Mast Head Float Comparison

Out of interest I borrowed a 9L crewsaver mast float to see how it compared to our milk bottle DIY mast float. This is probably more streamlined than the bottles as it’s very thin. Upon testing it held the mast well but not any better than the two milk bottles. It floated slightly below the water level which probably could have been improved had I tied it on better and blown it up a little more.

So what’s better? From my point of view it’s a clear win for the milk bottle. I’m yet to test it out long term so my view could change but the £50 mast floats aren’t worth the price tag.

What do you think? Let me know your ideas for mast floats. I’m sure there are other good ideas I’ve not thought of.

Cloyd Adams