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surfski_design_characteristics

Surfski Design Characteristics

Length

Generally longer means faster, at least on flat water. But all of the other characteristics below interplay with length to affect speed, and work differently in waves as opposed to flat water. The closer waves are together the more that length typically starts to interfere with turning and agility particularly for flat boats with little or no rocker.

Beam

The width at the widest point of a boat. Beam in surfskis occurs close to the seat and surfskis usually do not have abrupt transitions in width so beam can be used for general comparisons of surfski width - generally “narrower is faster” but less stable (flatness of the bottom interplays with this)

Chine

The transition shapes from the bottom to the sides of surfski (a hard chine is an abrupt transition or corner, a soft chine is a more gradual curve). Harder chines in a surfski can contribute to quirky or abrupt transitions in handling.

chine.jpg

Rocker

refers to the amount of curvature in the bottom of the hull along its length from bow to stern. More rocker reduces the tendency of a surfski to spear waves so the ends “rock” up. Rocker typically also makes a surfski easier to turn because resistance from the water against turning is more centralized and not extended as strongly to the bow and stern.

Volume

The inner space of a surfski that is more or less hollow and provides the overall degree of flotation for the ski. Larger paddlers generally need and prefer larger volume boats although expert paddlers can usually more efficiently paddle smaller surfskis. Larger volume can be preferred in bigger seas and surf. And volume interplays with shape and distribution of the volume in effects on handling. For example - more volume of air in the bow helps keep the bow above water better and also brings the boat back to the surface sooner if the boat does run into a wave.

Weight

Differences in weight in surfskis is primarily due to the use of different construction materials. Heavier fiberglass is less expensive. The more carbon that is used, generally the lighter and more expensive the boat. A heavier version of the same model will be more stable but slower to accelerate and slower overall on flatwater (though the added stability may result in greater speed in rougher conditions). Differences in weight may also be important in loading, unloading and carrying your surfski particularly if you have to do this on your own.

Cockpit Design Details

  • Seat Well - some paddlers find that most or all styles of surfski seat require additional padding (underneath, behind, or on sides) to achieve comfort and/or maximum stroke efficiency. Keep in mind that underseat padding tends to reduce stability by raising your center of gravity (but can also used as an aid in practicing and increasing stability). And try to avoid padding that interferes with hip rotation (needs to be slick or be covered with something slick to minimize friction). Otherwise you will reduce the benefit of leg drive for stroke power and possibly increase torque on your lower back from using torso rotation without adequate hip rotation.
    • Shape - as Bob Putnam says “every butt is different”. No brand's seat shape is better for all paddlers, it is the “butt/seat interface” between your boat seat and your rear and how well it works for you that is critical.
    • Width - you need enough space to comfortably sit and rotate your hips but at the same time you do not want your seat to be so loose that you slide sideways and/or cannot control sideways tilting with your hips.
    • Depth - A deeper seat well may lend a surfski greater stability if it is lowering your center of gravity in your boat. At the same time a deeper seat well can make remounts more difficult and may change the weight distribution (butt lower relative to feet and legs) in a way that can potentially put more strain on your lower back during stroke leg drive and rotation.
    • Seat Well Leg Hump - the location and height of a hump under your legs can limit your ability to straighten your legs and consequently limit your leg drive
  • Foot Pedals - you need to make sure that you have enough width to place your feet side by side without interference with each other when using the pedals. You also need to be able to move your pedals to a place that allows your legs to work best for getting maximum leg drive. Ease of adjustment of pedal position may be more important if more than one person will be using a surfski.
  • Foot Straps
  • Drains - primary difference in drain styles is ones that open and close manually and ones that are always open.
    • Always open drains allow water into the foot well when your surfski is moving slowly or is stopped. They typically are smaller than manual drain openings and some folks complain about some of their drainage speeds. Since you typically have more than one smaller drain of this style, the holes may be somewhat more subject to clogging.
    • Manual drains - you have to be able to easily reach and operate with your hand or foot which may be more of a nuisance. You can just leave this style open all of the time and let it operate like always open drains, but the drain flap that sticks down below your surfski when open may be more susceptible to damage if left open when loading, moving, or setting down your surfski. Also many of these style drains seem to lose their complete seal over time and start to leak even when closed which may be correctible by installing a new gasket if the drain construction allows this.
  • Leash Mounts - sturdy, recessed leash mounts are a plus. Some surfskis have them in the footwell area for easy attachment for a leg leash and some do not. Lacking a foot well mount, one can add one with sufficient fiberglass working skill or you can attach you leg leash to your foot straps (make sure that this is completely secure and does not interfere with your feet entry/exit and pedal use.) If you prefer using a waist leash with a mount behind your seat, some surfskis come with bungee holes behind the seat that can also serve as leash anchor mounts, or you can add mounts of you own - recessed ones glassed into the behind seat area will be stronger than a surface mount like a well nut. Some folks put a metal plate inside to spread stress on a mount over a larger area and increase their strength.
surfski_design_characteristics.txt · Last modified: 2021/07/21 19:27 by preavley