The first set of options that had to be finalized have to do with the construction materials for some of the structural elements of the boat and the interior furniture layout. Here’s what we decided:
The standard construction plan for the 5X is well defined and there aren’t many options available, which is fine, since Outremer and the architects (VPLP) have made what I consider to be very good choices. In catamarans of this size and performance level, you see two main approaches taken by builders. They either select full carbon fiber hulls, which are very light and very rigid, or they go with foam core GRP (Glass Reinforced Plastic, AKA fiberglass). Foam core is not as light as carbon, but it is lighter than standard GRP laminate and is very strong.
It might seem that carbon fiber is the perfect solution to the strength vs weight equation, but it’s not. Carbon is very expensive, typically you double the cost of the boat when building in all carbon. Its also very thin, so it transmits a lot of water noise into the interior of the boat when underway, which can wear on your nerves, and it isn’t very resistant to impacts, so hitting a whale, tree trunk or submerged container will do more damage, and it’s complicated and expensive to repair, which is a particular concern when getting work done in remote locations.
Foam core is heavier, but it is still very strong and does not transmit noise like carbon. It is not very resistant to impact though.
What Outremer and VPLP have done is to use a hybrid system that is a compromise between safety, weight and comfort. They use a solid GRP laminate in the hulls below the waterline. This adds some weight, but provides maximum strength and impact resistance, and it’s easy to repair if damaged. They use foam core for everything above the waterline to reduce weight where impact resistance is not as important, and they offer the option of several carbon fiber internal structural sections to reduce weight while retaining strength.
The main carbon options available for the 5X are the two main bulkheads (fore and aft of the salon) the salon roof, the rudders and rudder shafts, and the dinghy davits. We chose the bulkheads and the salon roof to be made in carbon. These two options reduce the weight of the boat by about 250 kg (500 lbs).
We decided against the rudders and shafts in carbon, as I didn’t want carbon below the waterline due to risk of impact damage and difficulty of repairs. We also decided against the carbon davits because this was a very expensive option that didn’t save much weight vs. the standard aluminum davits.
The interior layout options for the 5X can get pretty extensive. They will really work with you to design what you need, within reason, and will engage the designer (Frank Darnet) to work on the layout changes if needed. They also offer some standard options, for example having two cabins in the port hull instead of the owner’s suite and having a small “skipper’s cabin” in the forward sail locker compartment.
They offer different types of wood finishes and interior colors as well, and these have to be chosen early in the process as they take a while to manufacture. We really like the standard design selections for the interior finishes so we didn’t make any changes there.
We like the standard owner’s version design with the master suite in the port hull, and we don’t need a skipper’s cabin, but we do want to add a small office in the port companionway which gives us an extra workspace without taking over the dining table or nav station.
Other layout selections we made were the orientation of the beds in the aft cabins. These can be either longitudinal or transverse. We chose longitudinal, because we don’t want to have to clamber over each other when entering or leaving the bed.
We had to decide on the fridge, freezer and TV set locations as these all impact the interior furniture design and need to be determined well before the start of construction.
We chose a large, two drawer fridge in the salon, and a TV that slides out horizontally from behind the cupboards.
We also chose the option to have the dining table on telescopic legs with additional cushions so that the banquette can be converted into a double bed for guests.
The final decision we made for the interior design was the location of the watermaker. Some owners have installed it under the master bunk with a control panel inside the companionway closet. I don’t like this as it means I have to pull the bed apart to service the watermaker. Instead I asked for it to be installed in the port engine room. Since the control panel has to be within 2 meters of the watermaker, we are installing the panel in the side of the transom just above the top step. There will be a watertight door that we can open to access the watermaker controls.
Those are the big decisions that we had to make last week to keep things on schedule. There are plenty more decisions to be made, and I’ll post more details about them as we go along.