Neap Tides

Donna, Swimming with a neap tide (high, low, flood, ebb, slack, syzygy, or other tide) is more dependent on where you are swimming then on the tidal influences themselves. Most open ocean swims or coast line swims have very little tidal impact, while river, bay and channel swims can be greatly impacted. Good race coordinators know the tidal effects on the race course and will schedule the event to the time and date that is most suitable. This could be on a flood, slack or ebb; it all depends on the race. In swims such as the English Channel you try to swim during a neap tide, because you are swimming across some wicked cross currents. In the MIMS, where you are swimming with the currents, you want to go up the East river with a flood tide, swim the Harlem Channel with the flood to a slack tide and down the Hudson on the ebb. Swims like the Chesapeake Bay Bridge is set up to start at the end of the flood tide so that you cross the mid-channel during slack tide and end during the ebb.

Rob, I am glad to hear that race coordinators are well-informed about the tide changes in their regions. I never doubted they were. Then I suppose the neap tide situation would not be a concern, especially in swims that are close to land (unless it were to be in Canada). I live not too far from the equator, well closer than you do, so even though swimming during a neap tide is of some benefit, it would be less for me this close to the equator than others. Plus, my water depth is 24,000 feet between Roatan and Utila so the winds will create some of my biggest challenges (wind+current=waves). But there will be two places in my swim whereby swimming at neap will help: starting out I will have two currents going in opposite directions, and about 10 miles out, I will encounter another two currents going opposite directions. I am just very glad to know that race coordinators try to do their swim races during ebb or flood tides; that is also a very good time depending on the geography of the swim. I just thought this subject might be interesting to open water swimmers, especially if they are like me and hunting for that very best time to do them, because I always need all the help I can get. :rofl: Donna

The MIF puts on a swim called The Little Red Lighthouse each year. The course has changed from a 7.8 mile race to a 5.8 mile race but I believe the intention of the race director is to keep the average finish time around 2 hours. This is accomplished by tweaking the start time reletive to the tidal changes and a staggering of the start (having up to 8 waves of swimmers). The entire Manhattan Marathon is dependant on timing the tides right and there is a great chapter about this trial and error in The History of Open Water Marathon Swimming by Capt. Tim Johnson.

okay, i just looked up the definition of neap tide: A tide of decreased range, which occurs about every two weeks when the moon is at one quarter or three-quarters full. I think it would be wise for swim/race organizers to consider this when planning an event but the distance of the swim seems like a lesser factor than the duration of the swim. With a following current, one can cover a great distance (>20 miles) in the 6 to eight hour window. I would want a neap tide if planning a swim perpendicular to the current. It would certainly aid in keeping the field of swimmers more contained.

Hi Dave, Thank you for your reply. I normally always try to do all my ocean swims during Neap Tide, of course there is another one called Spring Tide, but Neap Tide is more favorable. For me where I live, our Neap Tide is 4 or 5 days before half-moon, and 4-5 days after half-moon. And of course this is totally separate from surface current which can be caused by wind which causes waves when a current and surface flow clash. A different problem. So, at least there is a particular time each month in which the tides are of less gravitational pull and swims can be scheduled for better conditions. During Neap Tides, all ocean waters have less movement thus aiding long swims. I was just wondering if long swims were ever considered during Neap Tide thus giving the swimmers a better shot at a possibly easier swim they could enjoy. Donna

I'd like to know if any of you open water swimmers ever schedule a long ocean swim (over 5 miles) during a neap tide as it is known to help a swimmer during that swim. Donna In the history of open water marathon swimming, the author discusses in depth the selection of tides for Manhattan Island Marathon record attempts. Apparently they swi mon spring tides if attempting a new record for the circuit. English channel swims are almost all done on neap tides but apparently a few fast crossings have been done on spring tides. The spring tide is riskier but apparently if you get thright day it can make for good swimming.

syzygy? There is a place in the desert in California called Zzyzx. Is it near there?

Syzygy tides occur twice a month, when the Sun and the Moon are in conjunction (lined up on the same side of Earth at the new Moon) and when they are in opposition (on opposite sides of Earth at the full Moon). In either case, the gravitational effects of the Sun and the Moon reinforce each other, and tidal range is increased.