Is it safe to swim in a pool or ocean after the drain site has scabbed over?

Always check with your surgeon for their recommendations. Once the liposuction sites are completely healed I tell my patients they can be under water, sometimes it's 3-4 weeks. Best wishes.

As soon as a drain side is healed I would permit my patients to swim. However, your restriction should come from your own surgeon.

The best person to evaluate your readiness to swim would be your surgeon.  While it is common to see the skin completely sealed under a scab, there can also remain a small opening that might preclude your body's readiness to swim.  In addition, you should discuss with your plastic surgeon how rigorous of a swim you can take given the surgery you had.