这里面涉及到“wash”的一个在日常生活中不常见的含义，除了常见的“清洗”等含义，“wash”还有很多其他含义，查阅ReversoDictionary后发现，“wash”作名词时可以表示“the wash of a boat is the wave that it causes on either side as it moves through the water”，就是船舶划过水面产生的波浪，而“Minimize Boat Wash”则是指“最大限度地减少船舶产生的波浪”，如果船舶过多地产生波浪，会对其他船舶、岸边结构、漂浮植物等造成损害。

例句：

原文：

The impact of wash will vary, depending on the waterway. In an open waterway, it might be okay to open the throttle and make a big wash, without causing any impact. In a narrow, sheltered waterway more care will be needed, because the shoreline might be more susceptible to erosion, or there are small craft could be affected. On some sensitive waterways, even the relatively small wash from fast planing vessels can still have an impact.

As a rule of thumb, if your vessel is making waves that are bigger than what you might reasonably expect in an area (from wind, swell etc), then there is a high risk that you might be causing problems – especially if you are close to shore or other vessels.

译文：

对于不同的航道，船舶产生的波浪所造成的影响会有所不同。若航道开阔，加大油门产生大浪，或许也不会造成任何影响。但是，在狭窄的遮蔽航道，海岸线更容易遭受侵蚀，或者会有小船经过，需要更加小心。在一些易受影响的航道，即使快速航行的船舶产生的波浪较小，也会产生影响。

按照经验来说，如果船舶产生的波浪比合理预期（因风、涌浪等因素）产生的波浪大，则极有可能出现问题，尤其是靠近岸边或其他船舶时。

来源：

ReversoDictionary

https://www.nsw.gov.au/sites/default/files/2021-03/Dont-make-waves.pdf