The best snorkel for freediving in Northern California
You can't go too wrong with whatever snorkel you buy, and it won't be a deal breaker for a dive day. Although many freedivers in calmer, tropical waters prefer an open-top snorkel for better airflow, I personally recommend you get a "dry" snorkel if you are going to freedive in the Pacific ocean.
Dry
Open-top snorkels are appropriate in calm conditions, like lakes, but for the Pacific ocean, a dry-top snorkel which provides protection from waves is a safer choice.
Easy to unclip
The best snorkels unclip easily from your mask, allowing you to store your mask in a case after every dive, which extends its life. For unclipping, a hinged mechanism is better than a static clip.