WIP: Scuba Diving Surface Interval Shrug

It is rare when I feel the need for a sweater in Hawai'i: Woe for a knitter!
But I felt the need this winter. The water in the Pacific around Hawaii has been about 5 degrees colder than last year, and I have felt the chill between dives. I have been wearing various sweatshirts and a knitted cap, but wouldn't a sweater be that much better?
Requirements for surface interval shrug:
Wool (exothermic in salt water)
Warm (the water is 71 degrees in winter and we have had rain, clouds, and crazy wind for the past 2 months)
Long sleeves, closely fitting, can be shoved up while bending over rinse tank or boat lines.
Short enough to not get wet from folded down wetsuit.
Long enough to keep torso warm.
Fold-up shawl collar for back of neck warmth, can be folded down if remaining in hooded vest.
Color: Nice with black wetsuit, swimsuit colors, and sunburn.
Washable: Not only from salt water but the microbes present in salt water.
This yarn is Cascade 220 superwash in a color very rare for my stash! I was reaching for the usual periwinkle blue when this dusky rust caught my eye.
Pattern is Aran Cabled Shrug in Kaya Wool... and here is a pisser: What is up with "Aran Weight"??? The pattern calls for Aran weight, Kaya is bulky, and the store owner said that Aran and Worsted are about the same thing. Can we just agree on WPI or something?
As it is: I have not gotten gauge at all (of course) but would like it tighter fit than the pattern calls for. We shall see.