Going Up and Down

The Sage 15 sloop and cat (aka, SageCat) are daggerboard boats. Many have asked, ‘why a daggerboard as all of Jerry Montgomery’s prior pocket cruisers are keel-centerboard types?’

When Sage Marine, ‘we’, started discussion about the Sage 15 we asked persons what they wanted in a 15′ trailer sailor pocket cruiser. Obviously there was a wide range in individual’s ‘wants and needs’ though themes were generated:

  • Ability to sit up on a seat in the cabin to get out of the weather.
  • Easy to use and store porta potty.
  • Comfortable berth.
  • Easy to sail single handed.
  • Easy to rig the boat single handed.
  • Ability to tow the boat with the family car.
  • Boat & trailer & mast fits inside a standard garage.
  • Easy to launch the boat on a shallow ramp.
  • Boat can be beached

In this post the I will begin discussing how the last four items on the above list as they directly relate to why the S15 is a daggerboard boat.

To answer ‘the final four’ design needs the boat must be made ‘less tall’. This requires the boat to sit lower on a trailer, and weigh less that Jerry’s prior keel-centerboard designs. Weighing less means less ballast. A centerboard could do this … but would not create enough ballast for a ‘stiff’ boat. A centerboard also bisects most of the cabin when there is no shoal keel.

It was decided a daggerboard with a bulb would be the solution. The boat’s center of effort was designed so the daggerboard is under the v-berth resulting in an open cabin when the boat is on the water (ie, daggerboard down). A bulbed daggerboard has significant ballast down low on a lever arm. The bulb provides, for a given about of lead, less weight (ie, ease towing boat with the family car) with greater righting moment than a boat with ballast in the keel.


Sage 15’s daggerboard

A daggerboard also provides for shallow draft for launching the boat (ie, ease of launching). The lack of a fixed keel means the boat can be easily beached and dried out. The daggerboard arrangement also gets the boat on trailer combination inside a garage with a standard height door (between 6’9” and 7′).

S15 on S15 trailer

A Sage 15 on a the custom designed Pacific trailer.

Now there are some concerns in using a daggerboard. I’ll cover these in the next post on this topic.

– Dave

2 thoughts on “Going Up and Down

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