Marc Scholten skates on Juneau ponds and lakes, whacking at the surface to learn whether it is safe for a game of hockey.
A small chip made by the top of his stick means it's time to play. But a series of cracks either signals "get off" or "finish the game quickly."
"I love to skate," Scholten said, who plays pickup hockey games every day at lunch when lakes and ponds are frozen. "But I pay attention to what's going on."
Scholten said Juneau's skating community has grown in the past few years since the city build the Treadwell Arena ice rink. He expects more skaters each year to spill out onto the lakes and ponds for more ice time.
Not every eager skater must use Scholten's stick-whacking technique to test the ice for an afternoon or evening of fun.
But Juneau parks supervisor Bob Grochow says some precautions should be taken because most people know little about the swirling waters under a frozen sheet.
For example, one of the city's most popular spots for skating, Twin Lakes, enjoys several inches of ice throughout the winter. But its still surface seen from Egan Drive can be deceptive as it doesn't show the water flowing below, Grochow said.
Some 28 culverts carrying runoff water from nearby mountains empty out into Twin Lakes. No matter the temperature, moving water under the ice can break the surface, which explains why dog mushers fall through rivers and lakes in the Bush while the temperature is a raging 50 degrees below, Scholten said.
Four inches of ice is considered by most as a safe level, and 6 inches would be generous enough for snowmobiles and ATVs.
"With these cold temperatures, it can easily put on an inch a day," Scholten said about a pond that joins Twin Lakes near the Pioneers' Home.
Pioneer Pond, as the hockey players call it, is one of the fastest-freezing Juneau waters because it's covered with shade most of the day and is on the receiving end of winds coming from the Lemon Creek Valley, Scholten said.
Ponds freeze quicker than lakes, but the larger bodies take longer to thaw, Scholten said. The latest he's ever skated in Juneau was in the first week of April.
One can see the thickness of ice by staring into the surface and looking for the bubbles under the sheet. Sometimes a crack may also reflect the depth of the ice.
Scholten said he has skated on ice as thin as an inch and a half, though it was on a pond only knee-deep.
"That's the risk I'll take any day to go skating," he said.
But Scholten isn't exactly a daredevil. One rule he keeps is to never go skating at night unless he inspected the ice earlier that day.
Many surfaces around Juneau that are popular skating spots are at chest-high level for adults. Risky skating with children on these spots is not recommended, Scholten said.
With even more variables characteristic of Juneau, such as sudden rains and warming temperatures, Scholten suggests the city should pay more attention to skating spots.
"I'd like to see the city get involved in more monitoring," he said.
All the city's ice skating resources now go into maintaining Treadwell Arena, Grochow said.
Before it was built, the city created an outdoor rink by flooding a field at Melvin Park, but even it was not reliable. At best, the winters had 70 to 80 days of skating, Grochow said.
"No week is the same, no winter is the same," he said. "There are a lot of variables."
Andrew Petty can be reached at email@example.com