Design Brief

The following is a repost from this forum topic on the Proaforum. I’ll try to keep both up to date if I make any changes.

I’ve been trying to figure out what kind of vaka to build ever since my project kind of flopped in 2015. I put a large amount of time into designing a 9.2m vaka which all around, I was really happy with. The problem presented itself though when I did a cost estimate for the boat: it came in at around 12,000€, with the ama and quite a bit of epoxy already on hand (see this post on my blog). So, back to the drawing board — but first, I need a really clear design brief, so that feature creep doesn’t get the better of me again! This topic is all about what I need; ideas on how to address those requirements will come in the ‘Concept’ thread later on. This thread draws heavily on my earlier design brief here.

The goals / must-haves are as follows:

  • Single-handed circumnavigation of the Baltic Sea in summertime
  • Ability to sail it solo non-stop on the way up (I hope it’s possible on such a small boat!)
  • Cost to completion, including equipment: 5000-6000€, or if that’s impossible, at least get it to day-sailing state within that budget
  • Buildable in a 5.5m garage
  • Seaworthy enough to survive if caught out
  • Sustained average speed of ~80-90NM/day (sailing time: 15-16 h/day)
  • Avoid having to pay harbor fees (tender maybe?)
  • Daysailable with 2 people
  • Suitable for the temperatures of the northern Baltic (summer averages: 10°C water, 15°C air)
  • Interior which stays dry (spray & condensation)

Some nice-to-haves:

  • Camper cruiser for 2 people
  • Capacity for enough stores for 2 weeks of single-handing
  • Sitting headroom (i.e. >105cm) when seated on the floor
  • Normal sitting headroom of 135-150cm
  • Battery, VHF, AIS, solar panels

What I don’t need:

  • Any pretenses of ocean crossing, you need a 35 footer for that
  • Comfortable interior seating / a proper saloon for two

With these requirements in hand, it’s clear the boat can’t be very large, ~6m to ~9m. Since I only have my garage (5.5m long) and renting a workshop is well and fully out of the question with that budget, the boat will likely have to have be built from two or more sections which are later glued or bolted together (or a 3-point proa?) so that I can even build it.

I do have a 5.8 meter ama on hand, almost ready.

— Marco

Building a voyaging proa on a student's budget