The answer to this question basically comes down to a little bit of math...
An annual subscription = $7.99/month or $95.88/year
$95.88 * 1 year = $95.88
A monthly subscription = $9.99/month
Let's say you surf only during the spring and summer months (6 months):
$9.99 * 6 months = $59.94
In this scenario, you would save $35.94 by only subscribing to Surfline Premium for the months that you surf. However, once you exceed 10 months of monthly usage per year, you would save money by subscribing to the $95.88 annual price as opposed to $99.90 for 10 months.
Why not go for the annual subscription? It might encourage you to throw on a wetsuit (and booties, and gloves, and a hood...) and get in the water during those fall and winter months.
You can start your free trial for a Premium subscription here.